/*
* Terminal emulator.
*/

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <limits.h>

#include <time.h>
#include <assert.h>
#include "putty.h"
#include "terminal.h"

#define poslt(p1,p2) ( (p1).y < (p2).y || ( (p1).y == (p2).y && (p1).x < (p2).x ) )
#define posle(p1,p2) ( (p1).y < (p2).y || ( (p1).y == (p2).y && (p1).x <= (p2).x ) )
#define poseq(p1,p2) ( (p1).y == (p2).y && (p1).x == (p2).x )
#define posdiff(p1,p2) ( ((p1).y - (p2).y) * (term->cols+1) + (p1).x - (p2).x )

/* Product-order comparisons for rectangular block selection. */
#define posPlt(p1,p2) ( (p1).y <= (p2).y && (p1).x < (p2).x )
#define posPle(p1,p2) ( (p1).y <= (p2).y && (p1).x <= (p2).x )

#define incpos(p) ( (p).x == term->cols ? ((p).x = 0, (p).y++, 1) : ((p).x++, 0) )
#define decpos(p) ( (p).x == 0 ? ((p).x = term->cols, (p).y--, 1) : ((p).x--, 0) )

#define VT52_PLUS

#define CL_ANSIMIN	0x0001	       /* Codes in all ANSI like terminals. */
#define CL_VT100	0x0002	       /* VT100 */
#define CL_VT100AVO	0x0004	       /* VT100 +AVO; 132x24 (not 132x14) & attrs */
#define CL_VT102	0x0008	       /* VT102 */
#define CL_VT220	0x0010	       /* VT220 */
#define CL_VT320	0x0020	       /* VT320 */
#define CL_VT420	0x0040	       /* VT420 */
#define CL_VT510	0x0080	       /* VT510, NB VT510 includes ANSI */
#define CL_VT340TEXT	0x0100	       /* VT340 extensions that appear in the VT420 */
#define CL_SCOANSI	0x1000	       /* SCOANSI not in ANSIMIN. */
#define CL_ANSI		0x2000	       /* ANSI ECMA-48 not in the VT100..VT420 */
#define CL_OTHER	0x4000	       /* Others, Xterm, linux, putty, dunno, etc */

#define TM_VT100	(CL_ANSIMIN|CL_VT100)
#define TM_VT100AVO	(TM_VT100|CL_VT100AVO)
#define TM_VT102	(TM_VT100AVO|CL_VT102)
#define TM_VT220	(TM_VT102|CL_VT220)
#define TM_VTXXX	(TM_VT220|CL_VT340TEXT|CL_VT510|CL_VT420|CL_VT320)
#define TM_SCOANSI	(CL_ANSIMIN|CL_SCOANSI)

#define TM_PUTTY	(0xFFFF)

#define UPDATE_DELAY    ((TICKSPERSEC+49)/50)/* ticks to defer window update */
#define TBLINK_DELAY    ((TICKSPERSEC*9+19)/20)/* ticks between text blinks*/
#define CBLINK_DELAY    (CURSORBLINK) /* ticks between cursor blinks */
#define VBELL_DELAY     (VBELL_TIMEOUT) /* visual bell timeout in ticks */

#define compatibility(x) \
	if ( ((CL_##x)&term->compatibility_level) == 0 ) { 	\
	term->termstate=TOPLEVEL;			\
	break;						\
	}
#define compatibility2(x,y) \
	if ( ((CL_##x|CL_##y)&term->compatibility_level) == 0 ) { \
	term->termstate=TOPLEVEL;			\
	break;						\
	}

#define has_compat(x) ( ((CL_##x)&term->compatibility_level) != 0 )

const char *EMPTY_WINDOW_TITLE = "";

const char sco2ansicolour[] = { 0, 4, 2, 6, 1, 5, 3, 7 };

#define sel_nl_sz  (sizeof(sel_nl)/sizeof(wchar_t))
const wchar_t sel_nl[] = SEL_NL;

/*
* Fetch the character at a particular position in a line array,
* for purposes of `wordtype'. The reason this isn't just a simple
* array reference is that if the character we find is UCSWIDE,
* then we must look one space further to the left.
*/
#define UCSGET(a, x) \
	( (x)>0 && (a)[(x)].chr == UCSWIDE ? (a)[(x)-1].chr : (a)[(x)].chr )

/*
* Detect the various aliases of U+0020 SPACE.
*/
#define IS_SPACE_CHR(chr) \
	((chr) == 0x20 || (DIRECT_CHAR(chr) && ((chr) & 0xFF) == 0x20))

/*
* Spot magic CSETs.
*/
#define CSET_OF(chr) (DIRECT_CHAR(chr)||DIRECT_FONT(chr) ? (chr)&CSET_MASK : 0)

/*
* Internal prototypes.
*/
static void resizeline(Terminal *, termline *, int);
static termline *lineptr(Terminal *, int, int, int);
static void unlineptr(termline *);
static void check_line_size(Terminal *, termline *);
static void do_paint(Terminal *, Context, int);
static void erase_lots(Terminal *, int, int, int);
static int find_last_nonempty_line(Terminal *, tree234 *);
static void swap_screen(Terminal *, int, int, int);
static void update_sbar(Terminal *);
static void deselect(Terminal *);
static void term_print_finish(Terminal *);
static void scroll(Terminal *, int, int, int, int);
#ifdef OPTIMISE_SCROLL
static void scroll_display(Terminal *, int, int, int);
#endif /* OPTIMISE_SCROLL */

static termline *newline(Terminal *term, int cols, int bce)
{
	termline *line;
	int j;

	line = snew(termline);
	line->chars = snewn(cols, termchar);
	for (j = 0; j < cols; j++)
		line->chars[j] = (bce ? term->erase_char : term->basic_erase_char);
	line->cols = line->size = cols;
	line->lattr = LATTR_NORM;
	line->temporary = FALSE;
	line->cc_free = 0;

	return line;
}

static void freeline(termline *line)
{
	if (line) {
		sfree(line->chars);
		sfree(line);
	}
}

static void unlineptr(termline *line)
{
	if (line->temporary)
		freeline(line);
}

#ifdef TERM_CC_DIAGS
/*
* Diagnostic function: verify that a termline has a correct
* combining character structure.
* 
* This is a performance-intensive check, so it's no longer enabled
* by default.
*/
static void cc_check(termline *line)
{
	unsigned char *flags;
	int i, j;

	assert(line->size >= line->cols);

	flags = snewn(line->size, unsigned char);

	for (i = 0; i < line->size; i++)
		flags[i] = (i < line->cols);

	for (i = 0; i < line->cols; i++) {
		j = i;
		while (line->chars[j].cc_next) {
			j += line->chars[j].cc_next;
			assert(j >= line->cols && j < line->size);
			assert(!flags[j]);
			flags[j] = TRUE;
		}
	}

	j = line->cc_free;
	if (j) {
		while (1) {
			assert(j >= line->cols && j < line->size);
			assert(!flags[j]);
			flags[j] = TRUE;
			if (line->chars[j].cc_next)
				j += line->chars[j].cc_next;
			else
				break;
		}
	}

	j = 0;
	for (i = 0; i < line->size; i++)
		j += (flags[i] != 0);

	assert(j == line->size);

	sfree(flags);
}
#endif

/*
* Add a combining character to a character cell.
*/
static void add_cc(termline *line, int col, unsigned long chr)
{
	int newcc;

	assert(col >= 0 && col < line->cols);

	/*
	* Start by extending the cols array if the free list is empty.
	*/
	if (!line->cc_free) {
		int n = line->size;
		line->size += 16 + (line->size - line->cols) / 2;
		line->chars = sresize(line->chars, line->size, termchar);
		line->cc_free = n;
		while (n < line->size) {
			if (n+1 < line->size)
				line->chars[n].cc_next = 1;
			else
				line->chars[n].cc_next = 0;
			n++;
		}
	}

	/*
	* Now walk the cc list of the cell in question.
	*/
	while (line->chars[col].cc_next)
		col += line->chars[col].cc_next;

	/*
	* `col' now points at the last cc currently in this cell; so
	* we simply add another one.
	*/
	newcc = line->cc_free;
	if (line->chars[newcc].cc_next)
		line->cc_free = newcc + line->chars[newcc].cc_next;
	else
		line->cc_free = 0;
	line->chars[newcc].cc_next = 0;
	line->chars[newcc].chr = chr;
	line->chars[col].cc_next = newcc - col;

#ifdef TERM_CC_DIAGS
	cc_check(line);
#endif
}

/*
* Clear the combining character list in a character cell.
*/
static void clear_cc(termline *line, int col)
{
	int oldfree, origcol = col;

	assert(col >= 0 && col < line->cols);

	if (!line->chars[col].cc_next)
		return;			       /* nothing needs doing */

	oldfree = line->cc_free;
	line->cc_free = col + line->chars[col].cc_next;
	while (line->chars[col].cc_next)
		col += line->chars[col].cc_next;
	if (oldfree)
		line->chars[col].cc_next = oldfree - col;
	else
		line->chars[col].cc_next = 0;

	line->chars[origcol].cc_next = 0;

#ifdef TERM_CC_DIAGS
	cc_check(line);
#endif
}

/*
* Compare two character cells for equality. Special case required
* in do_paint() where we override what we expect the chr and attr
* fields to be.
*/
static int termchars_equal_override(termchar *a, termchar *b,
	unsigned long bchr, unsigned long battr)
{
	/* FULL-TERMCHAR */
	if (a->chr != bchr)
		return FALSE;
	if ((a->attr &~ DATTR_MASK) != (battr &~ DATTR_MASK))
		return FALSE;
	while (a->cc_next || b->cc_next) {
		if (!a->cc_next || !b->cc_next)
			return FALSE;	       /* one cc-list ends, other does not */
		a += a->cc_next;
		b += b->cc_next;
		if (a->chr != b->chr)
			return FALSE;
	}
	return TRUE;
}

static int termchars_equal(termchar *a, termchar *b)
{
	return termchars_equal_override(a, b, b->chr, b->attr);
}

/*
* Copy a character cell. (Requires a pointer to the destination
* termline, so as to access its free list.)
*/
static void copy_termchar(termline *destline, int x, termchar *src)
{
	clear_cc(destline, x);

	destline->chars[x] = *src;	       /* copy everything except cc-list */
	destline->chars[x].cc_next = 0;    /* and make sure this is zero */

	while (src->cc_next) {
		src += src->cc_next;
		add_cc(destline, x, src->chr);
	}

#ifdef TERM_CC_DIAGS
	cc_check(destline);
#endif
}

/*
* Move a character cell within its termline.
*/
static void move_termchar(termline *line, termchar *dest, termchar *src)
{
	/* First clear the cc list from the original char, just in case. */
	clear_cc(line, dest - line->chars);

	/* Move the character cell and adjust its cc_next. */
	*dest = *src;		       /* copy everything except cc-list */
	if (src->cc_next)
		dest->cc_next = src->cc_next - (dest-src);

	/* Ensure the original cell doesn't have a cc list. */
	src->cc_next = 0;

#ifdef TERM_CC_DIAGS
	cc_check(line);
#endif
}

/*
* Compress and decompress a termline into an RLE-based format for
* storing in scrollback. (Since scrollback almost never needs to
* be modified and exists in huge quantities, this is a sensible
* tradeoff, particularly since it allows us to continue adding
* features to the main termchar structure without proportionally
* bloating the terminal emulator's memory footprint unless those
* features are in constant use.)
*/
struct buf {
	unsigned char *data;
	int len, size;
};
static void add(struct buf *b, unsigned char c)
{
	if (b->len >= b->size) {
		b->size = (b->len * 3 / 2) + 512;
		b->data = sresize(b->data, b->size, unsigned char);
	}
	b->data[b->len++] = c;
}
static int get(struct buf *b)
{
	return b->data[b->len++];
}
static void makerle(struct buf *b, termline *ldata,
	void (*makeliteral)(struct buf *b, termchar *c,
	unsigned long *state))
{
	int hdrpos, hdrsize, n, prevlen, prevpos, thislen, thispos, prev2;
	termchar *c = ldata->chars;
	unsigned long state = 0, oldstate;

	n = ldata->cols;

	hdrpos = b->len;
	hdrsize = 0;
	add(b, 0);
	prevlen = prevpos = 0;
	prev2 = FALSE;

	while (n-- > 0) {
		thispos = b->len;
		makeliteral(b, c++, &state);
		thislen = b->len - thispos;
		if (thislen == prevlen &&
			!memcmp(b->data + prevpos, b->data + thispos, thislen)) {
				/*
				* This literal precisely matches the previous one.
				* Turn it into a run if it's worthwhile.
				* 
				* With one-byte literals, it costs us two bytes to
				* encode a run, plus another byte to write the header
				* to resume normal output; so a three-element run is
				* neutral, and anything beyond that is unconditionally
				* worthwhile. With two-byte literals or more, even a
				* 2-run is a win.
				*/
				if (thislen > 1 || prev2) {
					int runpos, runlen;

					/*
					* It's worth encoding a run. Start at prevpos,
					* unless hdrsize==0 in which case we can back up
					* another one and start by overwriting hdrpos.
					*/

					hdrsize--;	       /* remove the literal at prevpos */
					if (prev2) {
						assert(hdrsize > 0);
						hdrsize--;
						prevpos -= prevlen;/* and possibly another one */
					}

					if (hdrsize == 0) {
						assert(prevpos == hdrpos + 1);
						runpos = hdrpos;
						b->len = prevpos+prevlen;
					} else {
						memmove(b->data + prevpos+1, b->data + prevpos, prevlen);
						runpos = prevpos;
						b->len = prevpos+prevlen+1;
						/*
						* Terminate the previous run of ordinary
						* literals.
						*/
						assert(hdrsize >= 1 && hdrsize <= 128);
						b->data[hdrpos] = hdrsize - 1;
					}

					runlen = prev2 ? 3 : 2;

					while (n > 0 && runlen < 129) {
						int tmppos, tmplen;
						tmppos = b->len;
						oldstate = state;
						makeliteral(b, c, &state);
						tmplen = b->len - tmppos;
						b->len = tmppos;
						if (tmplen != thislen ||
							memcmp(b->data + runpos+1, b->data + tmppos, tmplen)) {
								state = oldstate;
								break;	       /* run over */
						}
						n--, c++, runlen++;
					}

					assert(runlen >= 2 && runlen <= 129);
					b->data[runpos] = runlen + 0x80 - 2;

					hdrpos = b->len;
					hdrsize = 0;
					add(b, 0);
					/* And ensure this run doesn't interfere with the next. */
					prevlen = prevpos = 0;
					prev2 = FALSE;

					continue;
				} else {
					/*
					* Just flag that the previous two literals were
					* identical, in case we find a third identical one
					* we want to turn into a run.
					*/
					prev2 = TRUE;
					prevlen = thislen;
					prevpos = thispos;
				}
		} else {
			prev2 = FALSE;
			prevlen = thislen;
			prevpos = thispos;
		}

		/*
		* This character isn't (yet) part of a run. Add it to
		* hdrsize.
		*/
		hdrsize++;
		if (hdrsize == 128) {
			b->data[hdrpos] = hdrsize - 1;
			hdrpos = b->len;
			hdrsize = 0;
			add(b, 0);
			prevlen = prevpos = 0;
			prev2 = FALSE;
		}
	}

	/*
	* Clean up.
	*/
	if (hdrsize > 0) {
		assert(hdrsize <= 128);
		b->data[hdrpos] = hdrsize - 1;
	} else {
		b->len = hdrpos;
	}
}
static void makeliteral_chr(struct buf *b, termchar *c, unsigned long *state)
{
	/*
	* My encoding for characters is UTF-8-like, in that it stores
	* 7-bit ASCII in one byte and uses high-bit-set bytes as
	* introducers to indicate a longer sequence. However, it's
	* unlike UTF-8 in that it doesn't need to be able to
	* resynchronise, and therefore I don't want to waste two bits
	* per byte on having recognisable continuation characters.
	* Also I don't want to rule out the possibility that I may one
	* day use values 0x80000000-0xFFFFFFFF for interesting
	* purposes, so unlike UTF-8 I need a full 32-bit range.
	* Accordingly, here is my encoding:
	* 
	* 00000000-0000007F: 0xxxxxxx (but see below)
	* 00000080-00003FFF: 10xxxxxx xxxxxxxx
	* 00004000-001FFFFF: 110xxxxx xxxxxxxx xxxxxxxx
	* 00200000-0FFFFFFF: 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx
	* 10000000-FFFFFFFF: 11110ZZZ xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
	* 
	* (`Z' is like `x' but is always going to be zero since the
	* values I'm encoding don't go above 2^32. In principle the
	* five-byte form of the encoding could extend to 2^35, and
	* there could be six-, seven-, eight- and nine-byte forms as
	* well to allow up to 64-bit values to be encoded. But that's
	* completely unnecessary for these purposes!)
	* 
	* The encoding as written above would be very simple, except
	* that 7-bit ASCII can occur in several different ways in the
	* terminal data; sometimes it crops up in the D800 page
	* (CSET_ASCII) but at other times it's in the 0000 page (real
	* Unicode). Therefore, this encoding is actually _stateful_:
	* the one-byte encoding of 00-7F actually indicates `reuse the
	* upper three bytes of the last character', and to encode an
	* absolute value of 00-7F you need to use the two-byte form
	* instead.
	*/
	if ((c->chr & ~0x7F) == *state) {
		add(b, (unsigned char)(c->chr & 0x7F));
	} else if (c->chr < 0x4000) {
		add(b, (unsigned char)(((c->chr >> 8) & 0x3F) | 0x80));
		add(b, (unsigned char)(c->chr & 0xFF));
	} else if (c->chr < 0x200000) {
		add(b, (unsigned char)(((c->chr >> 16) & 0x1F) | 0xC0));
		add(b, (unsigned char)((c->chr >> 8) & 0xFF));
		add(b, (unsigned char)(c->chr & 0xFF));
	} else if (c->chr < 0x10000000) {
		add(b, (unsigned char)(((c->chr >> 24) & 0x0F) | 0xE0));
		add(b, (unsigned char)((c->chr >> 16) & 0xFF));
		add(b, (unsigned char)((c->chr >> 8) & 0xFF));
		add(b, (unsigned char)(c->chr & 0xFF));
	} else {
		add(b, 0xF0);
		add(b, (unsigned char)((c->chr >> 24) & 0xFF));
		add(b, (unsigned char)((c->chr >> 16) & 0xFF));
		add(b, (unsigned char)((c->chr >> 8) & 0xFF));
		add(b, (unsigned char)(c->chr & 0xFF));
	}
	*state = c->chr & ~0xFF;
}
static void makeliteral_attr(struct buf *b, termchar *c, unsigned long *state)
{
	/*
	* My encoding for attributes is 16-bit-granular and assumes
	* that the top bit of the word is never required. I either
	* store a two-byte value with the top bit clear (indicating
	* just that value), or a four-byte value with the top bit set
	* (indicating the same value with its top bit clear).
	* 
	* However, first I permute the bits of the attribute value, so
	* that the eight bits of colour (four in each of fg and bg)
	* which are never non-zero unless xterm 256-colour mode is in
	* use are placed higher up the word than everything else. This
	* ensures that attribute values remain 16-bit _unless_ the
	* user uses extended colour.
	*/
	unsigned attr, colourbits;

	attr = c->attr;

	assert(ATTR_BGSHIFT > ATTR_FGSHIFT);

	colourbits = (attr >> (ATTR_BGSHIFT + 4)) & 0xF;
	colourbits <<= 4;
	colourbits |= (attr >> (ATTR_FGSHIFT + 4)) & 0xF;

	attr = (((attr >> (ATTR_BGSHIFT + 8)) << (ATTR_BGSHIFT + 4)) |
		(attr & ((1 << (ATTR_BGSHIFT + 4))-1)));
	attr = (((attr >> (ATTR_FGSHIFT + 8)) << (ATTR_FGSHIFT + 4)) |
		(attr & ((1 << (ATTR_FGSHIFT + 4))-1)));

	attr |= (colourbits << (32-9));

	if (attr < 0x8000) {
		add(b, (unsigned char)((attr >> 8) & 0xFF));
		add(b, (unsigned char)(attr & 0xFF));
	} else {
		add(b, (unsigned char)(((attr >> 24) & 0x7F) | 0x80));
		add(b, (unsigned char)((attr >> 16) & 0xFF));
		add(b, (unsigned char)((attr >> 8) & 0xFF));
		add(b, (unsigned char)(attr & 0xFF));
	}
}
static void makeliteral_cc(struct buf *b, termchar *c, unsigned long *state)
{
	/*
	* For combining characters, I just encode a bunch of ordinary
	* chars using makeliteral_chr, and terminate with a \0
	* character (which I know won't come up as a combining char
	* itself).
	* 
	* I don't use the stateful encoding in makeliteral_chr.
	*/
	unsigned long zstate;
	termchar z;

	while (c->cc_next) {
		c += c->cc_next;

		assert(c->chr != 0);

		zstate = 0;
		makeliteral_chr(b, c, &zstate);
	}

	z.chr = 0;
	zstate = 0;
	makeliteral_chr(b, &z, &zstate);
}

static termline *decompressline(unsigned char *data, int *bytes_used);

static unsigned char *compressline(termline *ldata)
{
	struct buf buffer = { NULL, 0, 0 }, *b = &buffer;

	/*
	* First, store the column count, 7 bits at a time, least
	* significant `digit' first, with the high bit set on all but
	* the last.
	*/
	{
		int n = ldata->cols;
		while (n >= 128) {
			add(b, (unsigned char)((n & 0x7F) | 0x80));
			n >>= 7;
		}
		add(b, (unsigned char)(n));
	}

	/*
	* Next store the lattrs; same principle.
	*/
	{
		int n = ldata->lattr;
		while (n >= 128) {
			add(b, (unsigned char)((n & 0x7F) | 0x80));
			n >>= 7;
		}
		add(b, (unsigned char)(n));
	}

	/*
	* Now we store a sequence of separate run-length encoded
	* fragments, each containing exactly as many symbols as there
	* are columns in the ldata.
	* 
	* All of these have a common basic format:
	* 
	*  - a byte 00-7F indicates that X+1 literals follow it
	* 	- a byte 80-FF indicates that a single literal follows it
	* 	  and expects to be repeated (X-0x80)+2 times.
	* 
	* The format of the `literals' varies between the fragments.
	*/
	makerle(b, ldata, makeliteral_chr);
	makerle(b, ldata, makeliteral_attr);
	makerle(b, ldata, makeliteral_cc);

	/*
	* Diagnostics: ensure that the compressed data really does
	* decompress to the right thing.
	* 
	* This is a bit performance-heavy for production code.
	*/
#ifdef TERM_CC_DIAGS
#ifndef CHECK_SB_COMPRESSION
	{
		int dused;
		termline *dcl;
		int i;

#ifdef DIAGNOSTIC_SB_COMPRESSION
		for (i = 0; i < b->len; i++) {
			printf(" %02x ", b->data[i]);
		}
		printf("\n");
#endif

		dcl = decompressline(b->data, &dused);
		assert(b->len == dused);
		assert(ldata->cols == dcl->cols);
		assert(ldata->lattr == dcl->lattr);
		for (i = 0; i < ldata->cols; i++)
			assert(termchars_equal(&ldata->chars[i], &dcl->chars[i]));

#ifdef DIAGNOSTIC_SB_COMPRESSION
		printf("%d cols (%d bytes) -> %d bytes (factor of %g)\n",
			ldata->cols, 4 * ldata->cols, dused,
			(double)dused / (4 * ldata->cols));
#endif

		freeline(dcl);
	}
#endif
#endif /* TERM_CC_DIAGS */

	/*
	* Trim the allocated memory so we don't waste any, and return.
	*/
	return sresize(b->data, b->len, unsigned char);
}

static void readrle(struct buf *b, termline *ldata,
	void (*readliteral)(struct buf *b, termchar *c,
	termline *ldata, unsigned long *state))
{
	int n = 0;
	unsigned long state = 0;

	while (n < ldata->cols) {
		int hdr = get(b);

		if (hdr >= 0x80) {
			/* A run. */

			int pos = b->len, count = hdr + 2 - 0x80;
			while (count--) {
				assert(n < ldata->cols);
				b->len = pos;
				readliteral(b, ldata->chars + n, ldata, &state);
				n++;
			}
		} else {
			/* Just a sequence of consecutive literals. */

			int count = hdr + 1;
			while (count--) {
				assert(n < ldata->cols);
				readliteral(b, ldata->chars + n, ldata, &state);
				n++;
			}
		}
	}

	assert(n == ldata->cols);
}
static void readliteral_chr(struct buf *b, termchar *c, termline *ldata,
	unsigned long *state)
{
	int byte;

	/*
	* 00000000-0000007F: 0xxxxxxx
	* 00000080-00003FFF: 10xxxxxx xxxxxxxx
	* 00004000-001FFFFF: 110xxxxx xxxxxxxx xxxxxxxx
	* 00200000-0FFFFFFF: 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx
	* 10000000-FFFFFFFF: 11110ZZZ xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
	*/

	byte = get(b);
	if (byte < 0x80) {
		c->chr = byte | *state;
	} else if (byte < 0xC0) {
		c->chr = (byte &~ 0xC0) << 8;
		c->chr |= get(b);
	} else if (byte < 0xE0) {
		c->chr = (byte &~ 0xE0) << 16;
		c->chr |= get(b) << 8;
		c->chr |= get(b);
	} else if (byte < 0xF0) {
		c->chr = (byte &~ 0xF0) << 24;
		c->chr |= get(b) << 16;
		c->chr |= get(b) << 8;
		c->chr |= get(b);
	} else {
		assert(byte == 0xF0);
		c->chr = get(b) << 24;
		c->chr |= get(b) << 16;
		c->chr |= get(b) << 8;
		c->chr |= get(b);
	}
	*state = c->chr & ~0xFF;
}
static void readliteral_attr(struct buf *b, termchar *c, termline *ldata,
	unsigned long *state)
{
	unsigned val, attr, colourbits;

	val = get(b) << 8;
	val |= get(b);

	if (val >= 0x8000) {
		val &= ~0x8000;
		val <<= 16;
		val |= get(b) << 8;
		val |= get(b);
	}

	colourbits = (val >> (32-9)) & 0xFF;
	attr = (val & ((1<<(32-9))-1));

	attr = (((attr >> (ATTR_FGSHIFT + 4)) << (ATTR_FGSHIFT + 8)) |
		(attr & ((1 << (ATTR_FGSHIFT + 4))-1)));
	attr = (((attr >> (ATTR_BGSHIFT + 4)) << (ATTR_BGSHIFT + 8)) |
		(attr & ((1 << (ATTR_BGSHIFT + 4))-1)));

	attr |= (colourbits >> 4) << (ATTR_BGSHIFT + 4);
	attr |= (colourbits & 0xF) << (ATTR_FGSHIFT + 4);

	c->attr = attr;
}
static void readliteral_cc(struct buf *b, termchar *c, termline *ldata,
	unsigned long *state)
{
	termchar n;
	unsigned long zstate;
	int x = c - ldata->chars;

	c->cc_next = 0;

	while (1) {
		zstate = 0;
		readliteral_chr(b, &n, ldata, &zstate);
		if (!n.chr)
			break;
		add_cc(ldata, x, n.chr);
	}
}

static termline *decompressline(unsigned char *data, int *bytes_used)
{
	int ncols, byte, shift;
	struct buf buffer, *b = &buffer;
	termline *ldata;

	b->data = data;
	b->len = 0;

	/*
	* First read in the column count.
	*/
	ncols = shift = 0;
	do {
		byte = get(b);
		ncols |= (byte & 0x7F) << shift;
		shift += 7;
	} while (byte & 0x80);

	/*
	* Now create the output termline.
	*/
	ldata = snew(termline);
	ldata->chars = snewn(ncols, termchar);
	ldata->cols = ldata->size = ncols;
	ldata->temporary = TRUE;
	ldata->cc_free = 0;

	/*
	* We must set all the cc pointers in ldata->chars to 0 right
	* now, so that cc diagnostics that verify the integrity of the
	* whole line will make sense while we're in the middle of
	* building it up.
	*/
	{
		int i;
		for (i = 0; i < ldata->cols; i++)
			ldata->chars[i].cc_next = 0;
	}

	/*
	* Now read in the lattr.
	*/
	ldata->lattr = shift = 0;
	do {
		byte = get(b);
		ldata->lattr |= (byte & 0x7F) << shift;
		shift += 7;
	} while (byte & 0x80);

	/*
	* Now we read in each of the RLE streams in turn.
	*/
	readrle(b, ldata, readliteral_chr);
	readrle(b, ldata, readliteral_attr);
	readrle(b, ldata, readliteral_cc);

	/* Return the number of bytes read, for diagnostic purposes. */
	if (bytes_used)
		*bytes_used = b->len;

	return ldata;
}

/*
* Resize a line to make it `cols' columns wide.
*/
static void resizeline(Terminal *term, termline *line, int cols)
{
	int i, oldcols;

	if (line->cols != cols) {

		oldcols = line->cols;

		/*
		* This line is the wrong length, which probably means it
		* hasn't been accessed since a resize. Resize it now.
		* 
		* First, go through all the characters that will be thrown
		* out in the resize (if we're shrinking the line) and
		* return their cc lists to the cc free list.
		*/
		for (i = cols; i < oldcols; i++)
			clear_cc(line, i);

		/*
		* If we're shrinking the line, we now bodily move the
		* entire cc section from where it started to where it now
		* needs to be. (We have to do this before the resize, so
		* that the data we're copying is still there. However, if
		* we're expanding, we have to wait until _after_ the
		* resize so that the space we're copying into is there.)
		*/
		if (cols < oldcols)
			memmove(line->chars + cols, line->chars + oldcols,
			(line->size - line->cols) * TSIZE);

		/*
		* Now do the actual resize, leaving the _same_ amount of
		* cc space as there was to begin with.
		*/
		line->size += cols - oldcols;
		line->chars = sresize(line->chars, line->size, TTYPE);
		line->cols = cols;

		/*
		* If we're expanding the line, _now_ we move the cc
		* section.
		*/
		if (cols > oldcols)
			memmove(line->chars + cols, line->chars + oldcols,
			(line->size - line->cols) * TSIZE);

		/*
		* Go through what's left of the original line, and adjust
		* the first cc_next pointer in each list. (All the
		* subsequent ones are still valid because they are
		* relative offsets within the cc block.) Also do the same
		* to the head of the cc_free list.
		*/
		for (i = 0; i < oldcols && i < cols; i++)
			if (line->chars[i].cc_next)
				line->chars[i].cc_next += cols - oldcols;
		if (line->cc_free)
			line->cc_free += cols - oldcols;

		/*
		* And finally fill in the new space with erase chars. (We
		* don't have to worry about cc lists here, because we
		* _know_ the erase char doesn't have one.)
		*/
		for (i = oldcols; i < cols; i++)
			line->chars[i] = term->basic_erase_char;

#ifdef TERM_CC_DIAGS
		cc_check(line);
#endif
	}
}

/*
* Get the number of lines in the scrollback.
*/
static int sblines(Terminal *term)
{
	int sblines = count234(term->scrollback);
	if (term->erase_to_scrollback &&
		term->alt_which && term->alt_screen) {
			sblines += term->alt_sblines;
	}
	return sblines;
}

/*
* Retrieve a line of the screen or of the scrollback, according to
* whether the y coordinate is non-negative or negative
* (respectively).
*/
static termline *lineptr(Terminal *term, int y, int lineno, int screen)
{
	termline *line;
	tree234 *whichtree;
	int treeindex;

	if (y >= 0) {
		whichtree = term->screen;
		treeindex = y;
	} else {
		int altlines = 0;

		assert(!screen);

		if (term->erase_to_scrollback &&
			term->alt_which && term->alt_screen) {
				altlines = term->alt_sblines;
		}
		if (y < -altlines) {
			whichtree = term->scrollback;
			treeindex = y + altlines + count234(term->scrollback);
		} else {
			whichtree = term->alt_screen;
			treeindex = y + term->alt_sblines;
			/* treeindex = y + count234(term->alt_screen); */
		}
	}
	if (whichtree == term->scrollback) {
		unsigned char *cline = index234(whichtree, treeindex);
		line = decompressline(cline, NULL);
	} else {
		line = index234(whichtree, treeindex);
	}

	/* We assume that we don't screw up and retrieve something out of range. */
	if (line == NULL) {
		fatalbox("line==NULL in terminal.c\n"
			"lineno=%d y=%d w=%d h=%d\n"
			"count(scrollback=%p)=%d\n"
			"count(screen=%p)=%d\n"
			"count(alt=%p)=%d alt_sblines=%d\n"
			"whichtree=%p treeindex=%d\n\n"
			"Please contact <putty@projects.tartarus.org> "
			"and pass on the above information.",
			lineno, y, term->cols, term->rows,
			term->scrollback, count234(term->scrollback),
			term->screen, count234(term->screen),
			term->alt_screen, count234(term->alt_screen), term->alt_sblines,
			whichtree, treeindex);
	}
	assert(line != NULL);

	/*
	* Here we resize lines to _at least_ the right length, but we
	* don't truncate them. Truncation is done as a side effect of
	* modifying the line.
	*
	* The point of this policy is to try to arrange that resizing the
	* terminal window repeatedly - e.g. successive steps in an X11
	* opaque window-resize drag, or resizing as a side effect of
	* retiling by tiling WMs such as xmonad - does not throw away
	* data gratuitously. Specifically, we want a sequence of resize
	* operations with no terminal output between them to have the
	* same effect as a single resize to the ultimate terminal size,
	* and also (for the case in which xmonad narrows a window that's
	* scrolling things) we want scrolling up new text at the bottom
	* of a narrowed window to avoid truncating lines further up when
	* the window is re-widened.
	*/
	if (term->cols > line->cols)
		resizeline(term, line, term->cols);

	return line;
}

#define lineptr(x) (lineptr)(term,x,__LINE__,FALSE)
#define scrlineptr(x) (lineptr)(term,x,__LINE__,TRUE)

/*
* Coerce a termline to the terminal's current width. Unlike the
* optional resize in lineptr() above, this is potentially destructive
* of text, since it can shrink as well as grow the line.
*
* We call this whenever a termline is actually going to be modified.
* Helpfully, putting a single call to this function in check_boundary
* deals with _nearly_ all such cases, leaving only a few things like
* bulk erase and ESC#8 to handle separately.
*/
static void check_line_size(Terminal *term, termline *line)
{
	if (term->cols != line->cols)      /* trivial optimisation */
		resizeline(term, line, term->cols);
}

static void term_schedule_tblink(Terminal *term);
static void term_schedule_cblink(Terminal *term);

static void term_timer(void *ctx, unsigned long now)
{
	Terminal *term = (Terminal *)ctx;
	int update = FALSE;

	if (term->tblink_pending && now == term->next_tblink) {
		term->tblinker = !term->tblinker;
		term->tblink_pending = FALSE;
		term_schedule_tblink(term);
		update = TRUE;
	}

	if (term->cblink_pending && now == term->next_cblink) {
		term->cblinker = !term->cblinker;
		term->cblink_pending = FALSE;
		term_schedule_cblink(term);
		update = TRUE;
	}

	if (term->in_vbell && now == term->vbell_end) {
		term->in_vbell = FALSE;
		update = TRUE;
	}

	if (update ||
		(term->window_update_pending && now == term->next_update))
		term_update(term);
}

static void term_schedule_update(Terminal *term)
{
	if (!term->window_update_pending) {
		term->window_update_pending = TRUE;
		term->next_update = schedule_timer(UPDATE_DELAY, term_timer, term);
	}
}

/*
* Call this whenever the terminal window state changes, to queue
* an update.
*/
static void seen_disp_event(Terminal *term)
{
	term->seen_disp_event = TRUE;      /* for scrollback-reset-on-activity */
	term_schedule_update(term);
}

/*
* Call when the terminal's blinking-text settings change, or when
* a text blink has just occurred.
*/
static void term_schedule_tblink(Terminal *term)
{
	if (term->blink_is_real) {
		if (!term->tblink_pending)
			term->next_tblink = schedule_timer(TBLINK_DELAY, term_timer, term);
		term->tblink_pending = TRUE;
	} else {
		term->tblinker = 1;	       /* reset when not in use */
		term->tblink_pending = FALSE;
	}
}

/*
* Likewise with cursor blinks.
*/
static void term_schedule_cblink(Terminal *term)
{
	if (term->blink_cur && term->has_focus) {
		if (!term->cblink_pending)
			term->next_cblink = schedule_timer(CBLINK_DELAY, term_timer, term);
		term->cblink_pending = TRUE;
	} else {
		term->cblinker = 1;	       /* reset when not in use */
		term->cblink_pending = FALSE;
	}
}

/*
* Call to reset cursor blinking on new output.
*/
static void term_reset_cblink(Terminal *term)
{
	seen_disp_event(term);
	term->cblinker = 1;
	term->cblink_pending = FALSE;
	term_schedule_cblink(term);
}

/*
* Call to begin a visual bell.
*/
static void term_schedule_vbell(Terminal *term, int already_started,
	long startpoint)
{
	long ticks_already_gone;

	if (already_started)
		ticks_already_gone = GETTICKCOUNT() - startpoint;
	else
		ticks_already_gone = 0;

	if (ticks_already_gone < VBELL_DELAY) {
		term->in_vbell = TRUE;
		term->vbell_end = schedule_timer(VBELL_DELAY - ticks_already_gone,
			term_timer, term);
	} else {
		term->in_vbell = FALSE;
	}
}

/*
* Set up power-on settings for the terminal.
* If 'clear' is false, don't actually clear the primary screen, and
* position the cursor below the last non-blank line (scrolling if
* necessary).
*/
static void power_on(Terminal *term, int clear)
{
	term->alt_x = term->alt_y = 0;
	term->savecurs.x = term->savecurs.y = 0;
	term->alt_savecurs.x = term->alt_savecurs.y = 0;
	term->alt_t = term->marg_t = 0;
	if (term->rows != -1)
		term->alt_b = term->marg_b = term->rows - 1;
	else
		term->alt_b = term->marg_b = 0;
	if (term->cols != -1) {
		int i;
		for (i = 0; i < term->cols; i++)
			term->tabs[i] = (i % 8 == 0 ? TRUE : FALSE);
	}
	term->alt_om = term->dec_om = conf_get_int(term->conf, CONF_dec_om);
	term->alt_ins = term->insert = FALSE;
	term->alt_wnext = term->wrapnext =
		term->save_wnext = term->alt_save_wnext = FALSE;
	term->alt_wrap = term->wrap = conf_get_int(term->conf, CONF_wrap_mode);
	term->alt_cset = term->cset = term->save_cset = term->alt_save_cset = 0;
	term->alt_utf = term->utf = term->save_utf = term->alt_save_utf = 0;
	term->utf_state = 0;
	term->alt_sco_acs = term->sco_acs =
		term->save_sco_acs = term->alt_save_sco_acs = 0;
	term->cset_attr[0] = term->cset_attr[1] =
		term->save_csattr = term->alt_save_csattr = CSET_ASCII;
	term->rvideo = 0;
	term->in_vbell = FALSE;
	term->cursor_on = 1;
	term->big_cursor = 0;
	term->default_attr = term->save_attr =
		term->alt_save_attr = term->curr_attr = ATTR_DEFAULT;
	term->term_editing = term->term_echoing = FALSE;
	term->app_cursor_keys = conf_get_int(term->conf, CONF_app_cursor);
	term->app_keypad_keys = conf_get_int(term->conf, CONF_app_keypad);
	term->use_bce = conf_get_int(term->conf, CONF_bce);
	term->blink_is_real = conf_get_int(term->conf, CONF_blinktext);
	term->erase_char = term->basic_erase_char;
	term->alt_which = 0;
	term_print_finish(term);
	term->xterm_mouse = 0;
	term->xterm_extended_mouse = 0;
	term->urxvt_extended_mouse = 0;
	set_raw_mouse_mode(term->frontend, FALSE);
	term->bracketed_paste = FALSE;
	{
		int i;
		for (i = 0; i < 256; i++)
			term->wordness[i] = conf_get_int_int(term->conf, CONF_wordness, i);
	}
	if (term->screen) {
		swap_screen(term, 1, FALSE, FALSE);
		erase_lots(term, FALSE, TRUE, TRUE);
		swap_screen(term, 0, FALSE, FALSE);
		if (clear)
			erase_lots(term, FALSE, TRUE, TRUE);
		term->curs.y = find_last_nonempty_line(term, term->screen) + 1;
		if (term->curs.y == term->rows) {
			term->curs.y--;
			scroll(term, 0, term->rows - 1, 1, TRUE);
		}
	} else {
		term->curs.y = 0;
	}
	term->curs.x = 0;
	term_schedule_tblink(term);
	term_schedule_cblink(term);
}

/*
* Force a screen update.
*/
void term_update(Terminal *term)
{
	Context ctx;

	term->window_update_pending = FALSE;

	ctx = get_ctx(term->frontend);
	if (ctx) {
		int need_sbar_update = term->seen_disp_event;
		if (term->seen_disp_event && term->scroll_on_disp) {
			term->disptop = 0;	       /* return to main screen */
			term->seen_disp_event = 0;
			need_sbar_update = TRUE;
		}

		if (need_sbar_update)
			update_sbar(term);
		do_paint(term, ctx, TRUE);
		sys_cursor(term->frontend, term->curs.x, term->curs.y - term->disptop);
		free_ctx(ctx);
	}
}

/*
* Called from front end when a keypress occurs, to trigger
* anything magical that needs to happen in that situation.
*/
void term_seen_key_event(Terminal *term)
{
	/*
	* On any keypress, clear the bell overload mechanism
	* completely, on the grounds that large numbers of
	* beeps coming from deliberate key action are likely
	* to be intended (e.g. beeps from filename completion
	* blocking repeatedly).
	*/
	term->beep_overloaded = FALSE;
	while (term->beephead) {
		struct beeptime *tmp = term->beephead;
		term->beephead = tmp->next;
		sfree(tmp);
	}
	term->beeptail = NULL;
	term->nbeeps = 0;

	/*
	* Reset the scrollback on keypress, if we're doing that.
	*/
	if (term->scroll_on_key) {
		term->disptop = 0;	       /* return to main screen */
		seen_disp_event(term);
	}
}

/*
* Same as power_on(), but an external function.
*/
void term_pwron(Terminal *term, int clear)
{
	power_on(term, clear);
	if (term->ldisc)		       /* cause ldisc to notice changes */
		ldisc_echoedit_update(term->ldisc);
	term->disptop = 0;
	deselect(term);
	term_update(term);
}

static void set_erase_char(Terminal *term)
{
	term->erase_char = term->basic_erase_char;
	if (term->use_bce)
		term->erase_char.attr = (term->curr_attr &
		(ATTR_FGMASK | ATTR_BGMASK));
}

/*
* We copy a bunch of stuff out of the Conf structure into local
* fields in the Terminal structure, to avoid the repeated tree234
* lookups which would be involved in fetching them from the former
* every time.
*/
void term_copy_stuff_from_conf(Terminal *term)
{
	term->ansi_colour = conf_get_int(term->conf, CONF_ansi_colour);
	term->arabicshaping = conf_get_int(term->conf, CONF_arabicshaping);
	term->beep = conf_get_int(term->conf, CONF_beep);
	term->bellovl = conf_get_int(term->conf, CONF_bellovl);
	term->bellovl_n = conf_get_int(term->conf, CONF_bellovl_n);
	term->bellovl_s = conf_get_int(term->conf, CONF_bellovl_s);
	term->bellovl_t = conf_get_int(term->conf, CONF_bellovl_t);
	term->bidi = conf_get_int(term->conf, CONF_bidi);
	term->bksp_is_delete = conf_get_int(term->conf, CONF_bksp_is_delete);
	term->blink_cur = conf_get_int(term->conf, CONF_blink_cur);
	term->blinktext = conf_get_int(term->conf, CONF_blinktext);
	term->cjk_ambig_wide = conf_get_int(term->conf, CONF_cjk_ambig_wide);
	term->conf_height = conf_get_int(term->conf, CONF_height);
	term->conf_width = conf_get_int(term->conf, CONF_width);
	term->crhaslf = conf_get_int(term->conf, CONF_crhaslf);
	term->erase_to_scrollback = conf_get_int(term->conf, CONF_erase_to_scrollback);
	term->funky_type = conf_get_int(term->conf, CONF_funky_type);
	term->lfhascr = conf_get_int(term->conf, CONF_lfhascr);
	term->logflush = conf_get_int(term->conf, CONF_logflush);
	term->logtype = conf_get_int(term->conf, CONF_logtype);
	term->mouse_override = conf_get_int(term->conf, CONF_mouse_override);
	term->nethack_keypad = conf_get_int(term->conf, CONF_nethack_keypad);
	term->no_alt_screen = conf_get_int(term->conf, CONF_no_alt_screen);
	term->no_applic_c = conf_get_int(term->conf, CONF_no_applic_c);
	term->no_applic_k = conf_get_int(term->conf, CONF_no_applic_k);
	term->no_dbackspace = conf_get_int(term->conf, CONF_no_dbackspace);
	term->no_mouse_rep = conf_get_int(term->conf, CONF_no_mouse_rep);
	term->no_remote_charset = conf_get_int(term->conf, CONF_no_remote_charset);
	term->no_remote_resize = conf_get_int(term->conf, CONF_no_remote_resize);
	term->no_remote_wintitle = conf_get_int(term->conf, CONF_no_remote_wintitle);
	term->no_remote_clearscroll = conf_get_int(term->conf, CONF_no_remote_clearscroll);
	term->rawcnp = conf_get_int(term->conf, CONF_rawcnp);
	term->rect_select = conf_get_int(term->conf, CONF_rect_select);
	term->remote_qtitle_action = conf_get_int(term->conf, CONF_remote_qtitle_action);
	term->rxvt_homeend = conf_get_int(term->conf, CONF_rxvt_homeend);
	term->scroll_on_disp = conf_get_int(term->conf, CONF_scroll_on_disp);
	term->scroll_on_key = conf_get_int(term->conf, CONF_scroll_on_key);
	term->xterm_256_colour = conf_get_int(term->conf, CONF_xterm_256_colour);

	/*
	* Parse the control-character escapes in the configured
	* answerback string.
	*/
	{
		char *answerback = conf_get_str(term->conf, CONF_answerback);
		int maxlen = strlen(answerback);

		term->answerback = snewn(maxlen, char);
		term->answerbacklen = 0;

		while (*answerback) {
			char *n;
			char c = ctrlparse(answerback, &n);
			if (n) {
				term->answerback[term->answerbacklen++] = c;
				answerback = n;
			} else {
				term->answerback[term->answerbacklen++] = *answerback++;
			}
		}
	}
}

/*
* When the user reconfigures us, we need to check the forbidden-
* alternate-screen config option, disable raw mouse mode if the
* user has disabled mouse reporting, and abandon a print job if
* the user has disabled printing.
*/
void term_reconfig(Terminal *term, Conf *conf)
{
	/*
	* Before adopting the new config, check all those terminal
	* settings which control power-on defaults; and if they've
	* changed, we will modify the current state as well as the
	* default one. The full list is: Auto wrap mode, DEC Origin
	* Mode, BCE, blinking text, character classes.
	*/
	int reset_wrap, reset_decom, reset_bce, reset_tblink, reset_charclass;
	int i;

	reset_wrap = (conf_get_int(term->conf, CONF_wrap_mode) !=
		conf_get_int(conf, CONF_wrap_mode));
	reset_decom = (conf_get_int(term->conf, CONF_dec_om) !=
		conf_get_int(conf, CONF_dec_om));
	reset_bce = (conf_get_int(term->conf, CONF_bce) !=
		conf_get_int(conf, CONF_bce));
	reset_tblink = (conf_get_int(term->conf, CONF_blinktext) !=
		conf_get_int(conf, CONF_blinktext));
	reset_charclass = 0;
	for (i = 0; i < 256; i++)
		if (conf_get_int_int(term->conf, CONF_wordness, i) !=
			conf_get_int_int(conf, CONF_wordness, i))
			reset_charclass = 1;

	/*
	* If the bidi or shaping settings have changed, flush the bidi
	* cache completely.
	*/
	if (conf_get_int(term->conf, CONF_arabicshaping) !=
		conf_get_int(conf, CONF_arabicshaping) ||
		conf_get_int(term->conf, CONF_bidi) !=
		conf_get_int(conf, CONF_bidi)) {
			for (i = 0; i < term->bidi_cache_size; i++) {
				sfree(term->pre_bidi_cache[i].chars);
				sfree(term->post_bidi_cache[i].chars);
				term->pre_bidi_cache[i].width = -1;
				term->pre_bidi_cache[i].chars = NULL;
				term->post_bidi_cache[i].width = -1;
				term->post_bidi_cache[i].chars = NULL;
			}
	}

	conf_free(term->conf);
	term->conf = conf_copy(conf);

	if (reset_wrap)
		term->alt_wrap = term->wrap = conf_get_int(term->conf, CONF_wrap_mode);
	if (reset_decom)
		term->alt_om = term->dec_om = conf_get_int(term->conf, CONF_dec_om);
	if (reset_bce) {
		term->use_bce = conf_get_int(term->conf, CONF_bce);
		set_erase_char(term);
	}
	if (reset_tblink) {
		term->blink_is_real = conf_get_int(term->conf, CONF_blinktext);
	}
	if (reset_charclass)
		for (i = 0; i < 256; i++)
			term->wordness[i] = conf_get_int_int(term->conf, CONF_wordness, i);

	if (conf_get_int(term->conf, CONF_no_alt_screen))
		swap_screen(term, 0, FALSE, FALSE);
	if (conf_get_int(term->conf, CONF_no_mouse_rep)) {
		term->xterm_mouse = 0;
		set_raw_mouse_mode(term->frontend, 0);
	}
	if (conf_get_int(term->conf, CONF_no_remote_charset)) {
		term->cset_attr[0] = term->cset_attr[1] = CSET_ASCII;
		term->sco_acs = term->alt_sco_acs = 0;
		term->utf = 0;
	}
	if (!conf_get_str(term->conf, CONF_printer)) {
		term_print_finish(term);
	}
	term_schedule_tblink(term);
	term_schedule_cblink(term);
	term_copy_stuff_from_conf(term);
}

/*
* Clear the scrollback.
*/
void term_clrsb(Terminal *term)
{
	unsigned char *line;
	int i;

	/*
	* Scroll forward to the current screen, if we were back in the
	* scrollback somewhere until now.
	*/
	term->disptop = 0;

	/*
	* Clear the actual scrollback.
	*/
	while ((line = delpos234(term->scrollback, 0)) != NULL) {
		sfree(line);            /* this is compressed data, not a termline */
	}

	/*
	* When clearing the scrollback, we also truncate any termlines on
	* the current screen which have remembered data from a previous
	* larger window size. Rationale: clearing the scrollback is
	* sometimes done to protect privacy, so the user intention is
	* specifically that we should not retain evidence of what
	* previously happened in the terminal, and that ought to include
	* evidence to the right as well as evidence above.
	*/
	for (i = 0; i < term->rows; i++)
		check_line_size(term, scrlineptr(i));

	/*
	* There are now no lines of real scrollback which can be pulled
	* back into the screen by a resize, and no lines of the alternate
	* screen which should be displayed as if part of the scrollback.
	*/
	term->tempsblines = 0;
	term->alt_sblines = 0;

	/*
	* Update the scrollbar to reflect the new state of the world.
	*/
	update_sbar(term);
}

/*
* Initialise the terminal.
*/
Terminal *term_init(Conf *myconf, struct unicode_data *ucsdata,
	void *frontend)
{
	Terminal *term;

	/*
	* Allocate a new Terminal structure and initialise the fields
	* that need it.
	*/
	term = snew(Terminal);
	term->frontend = frontend;
	term->ucsdata = ucsdata;
	term->conf = conf_copy(myconf);
	term->logctx = NULL;
	term->compatibility_level = TM_PUTTY;
	strcpy(term->id_string, "\033[?6c");
	term->cblink_pending = term->tblink_pending = FALSE;
	term->paste_buffer = NULL;
	term->paste_len = 0;
	bufchain_init(&term->inbuf);
	bufchain_init(&term->printer_buf);
	term->printing = term->only_printing = FALSE;
	term->print_job = NULL;
	term->vt52_mode = FALSE;
	term->cr_lf_return = FALSE;
	term->seen_disp_event = FALSE;
	term->mouse_is_down = FALSE;
	term->reset_132 = FALSE;
	term->cblinker = term->tblinker = 0;
	term->has_focus = 1;
	term->repeat_off = FALSE;
	term->termstate = TOPLEVEL;
	term->selstate = NO_SELECTION;
	term->curstype = 0;

	term_copy_stuff_from_conf(term);

	term->screen = term->alt_screen = term->scrollback = NULL;
	term->tempsblines = 0;
	term->alt_sblines = 0;
	term->disptop = 0;
	term->disptext = NULL;
	term->dispcursx = term->dispcursy = -1;
	term->tabs = NULL;
	deselect(term);
	term->rows = term->cols = -1;
	power_on(term, TRUE);
	term->beephead = term->beeptail = NULL;
#ifdef OPTIMISE_SCROLL
	term->scrollhead = term->scrolltail = NULL;
#endif /* OPTIMISE_SCROLL */
	term->nbeeps = 0;
	term->lastbeep = FALSE;
	term->beep_overloaded = FALSE;
	term->attr_mask = 0xffffffff;
	term->resize_fn = NULL;
	term->resize_ctx = NULL;
	term->in_term_out = FALSE;
	term->ltemp = NULL;
	term->ltemp_size = 0;
	term->wcFrom = NULL;
	term->wcTo = NULL;
	term->wcFromTo_size = 0;

	term->window_update_pending = FALSE;

	term->bidi_cache_size = 0;
	term->pre_bidi_cache = term->post_bidi_cache = NULL;

	/* FULL-TERMCHAR */
	term->basic_erase_char.chr = CSET_ASCII | ' ';
	term->basic_erase_char.attr = ATTR_DEFAULT;
	term->basic_erase_char.cc_next = 0;
	term->erase_char = term->basic_erase_char;

	return term;
}

void term_free(Terminal *term)
{
	termline *line;
	struct beeptime *beep;
	int i;

	while ((line = delpos234(term->scrollback, 0)) != NULL)
		sfree(line);		       /* compressed data, not a termline */
	freetree234(term->scrollback);
	while ((line = delpos234(term->screen, 0)) != NULL)
		freeline(line);
	freetree234(term->screen);
	while ((line = delpos234(term->alt_screen, 0)) != NULL)
		freeline(line);
	freetree234(term->alt_screen);
	if (term->disptext) {
		for (i = 0; i < term->rows; i++)
			freeline(term->disptext[i]);
	}
	sfree(term->disptext);
	while (term->beephead) {
		beep = term->beephead;
		term->beephead = beep->next;
		sfree(beep);
	}
	bufchain_clear(&term->inbuf);
	if(term->print_job)
		printer_finish_job(term->print_job);
	bufchain_clear(&term->printer_buf);
	sfree(term->paste_buffer);
	sfree(term->ltemp);
	sfree(term->wcFrom);
	sfree(term->wcTo);

	for (i = 0; i < term->bidi_cache_size; i++) {
		sfree(term->pre_bidi_cache[i].chars);
		sfree(term->post_bidi_cache[i].chars);
		sfree(term->post_bidi_cache[i].forward);
		sfree(term->post_bidi_cache[i].backward);
	}
	sfree(term->pre_bidi_cache);
	sfree(term->post_bidi_cache);

	sfree(term->tabs);

	expire_timer_context(term);

	conf_free(term->conf);

	sfree(term);
}

/*
* Set up the terminal for a given size.
*/
void term_size(Terminal *term, int newrows, int newcols, int newsavelines)
{
	tree234 *newalt;
	termline **newdisp, *line;
	int i, j, oldrows = term->rows;
	int sblen;
	int save_alt_which = term->alt_which;

	if (newrows == term->rows && newcols == term->cols &&
		newsavelines == term->savelines)
		return;			       /* nothing to do */

	/* Behave sensibly if we're given zero (or negative) rows/cols */

	if (newrows < 1) newrows = 1;
	if (newcols < 1) newcols = 1;

	deselect(term);
	swap_screen(term, 0, FALSE, FALSE);

	term->alt_t = term->marg_t = 0;
	term->alt_b = term->marg_b = newrows - 1;

	if (term->rows == -1) {
		term->scrollback = newtree234(NULL);
		term->screen = newtree234(NULL);
		term->tempsblines = 0;
		term->rows = 0;
	}

	/*
	* Resize the screen and scrollback. We only need to shift
	* lines around within our data structures, because lineptr()
	* will take care of resizing each individual line if
	* necessary. So:
	* 
	*  - If the new screen is longer, we shunt lines in from temporary
	*    scrollback if possible, otherwise we add new blank lines at
	*    the bottom.
	*
	*  - If the new screen is shorter, we remove any blank lines at
	*    the bottom if possible, otherwise shunt lines above the cursor
	*    to scrollback if possible, otherwise delete lines below the
	*    cursor.
	* 
	*  - Then, if the new scrollback length is less than the
	*    amount of scrollback we actually have, we must throw some
	*    away.
	*/
	sblen = count234(term->scrollback);
	/* Do this loop to expand the screen if newrows > rows */
	assert(term->rows == count234(term->screen));
	while (term->rows < newrows) {
		if (term->tempsblines > 0) {
			unsigned char *cline;
			/* Insert a line from the scrollback at the top of the screen. */
			assert(sblen >= term->tempsblines);
			cline = delpos234(term->scrollback, --sblen);
			line = decompressline(cline, NULL);
			sfree(cline);
			line->temporary = FALSE;   /* reconstituted line is now real */
			term->tempsblines -= 1;
			addpos234(term->screen, line, 0);
			term->curs.y += 1;
			term->savecurs.y += 1;
			term->alt_y += 1;
			term->alt_savecurs.y += 1;
		} else {
			/* Add a new blank line at the bottom of the screen. */
			line = newline(term, newcols, FALSE);
			addpos234(term->screen, line, count234(term->screen));
		}
		term->rows += 1;
	}
	/* Do this loop to shrink the screen if newrows < rows */
	while (term->rows > newrows) {
		if (term->curs.y < term->rows - 1) {
			/* delete bottom row, unless it contains the cursor */
			line = delpos234(term->screen, term->rows - 1);
			freeline(line);
		} else {
			/* push top row to scrollback */
			line = delpos234(term->screen, 0);
			addpos234(term->scrollback, compressline(line), sblen++);
			freeline(line);
			term->tempsblines += 1;
			term->curs.y -= 1;
			term->savecurs.y -= 1;
			term->alt_y -= 1;
			term->alt_savecurs.y -= 1;
		}
		term->rows -= 1;
	}
	assert(term->rows == newrows);
	assert(count234(term->screen) == newrows);

	/* Delete any excess lines from the scrollback. */
	while (sblen > newsavelines) {
		line = delpos234(term->scrollback, 0);
		sfree(line);
		sblen--;
	}
	if (sblen < term->tempsblines)
		term->tempsblines = sblen;
	assert(count234(term->scrollback) <= newsavelines);
	assert(count234(term->scrollback) >= term->tempsblines);
	term->disptop = 0;

	/* Make a new displayed text buffer. */
	newdisp = snewn(newrows, termline *);
	for (i = 0; i < newrows; i++) {
		newdisp[i] = newline(term, newcols, FALSE);
		for (j = 0; j < newcols; j++)
			newdisp[i]->chars[j].attr = ATTR_INVALID;
	}
	if (term->disptext) {
		for (i = 0; i < oldrows; i++)
			freeline(term->disptext[i]);
	}
	sfree(term->disptext);
	term->disptext = newdisp;
	term->dispcursx = term->dispcursy = -1;

	/* Make a new alternate screen. */
	newalt = newtree234(NULL);
	for (i = 0; i < newrows; i++) {
		line = newline(term, newcols, TRUE);
		addpos234(newalt, line, i);
	}
	if (term->alt_screen) {
		while (NULL != (line = delpos234(term->alt_screen, 0)))
			freeline(line);
		freetree234(term->alt_screen);
	}
	term->alt_screen = newalt;
	term->alt_sblines = 0;

	term->tabs = sresize(term->tabs, newcols, unsigned char);
	{
		int i;
		for (i = (term->cols > 0 ? term->cols : 0); i < newcols; i++)
			term->tabs[i] = (i % 8 == 0 ? TRUE : FALSE);
	}

	/* Check that the cursor positions are still valid. */
	if (term->savecurs.y < 0)
		term->savecurs.y = 0;
	if (term->savecurs.y >= newrows)
		term->savecurs.y = newrows - 1;
	if (term->savecurs.x >= newcols)
		term->savecurs.x = newcols - 1;
	if (term->alt_savecurs.y < 0)
		term->alt_savecurs.y = 0;
	if (term->alt_savecurs.y >= newrows)
		term->alt_savecurs.y = newrows - 1;
	if (term->alt_savecurs.x >= newcols)
		term->alt_savecurs.x = newcols - 1;
	if (term->curs.y < 0)
		term->curs.y = 0;
	if (term->curs.y >= newrows)
		term->curs.y = newrows - 1;
	if (term->curs.x >= newcols)
		term->curs.x = newcols - 1;
	if (term->alt_y < 0)
		term->alt_y = 0;
	if (term->alt_y >= newrows)
		term->alt_y = newrows - 1;
	if (term->alt_x >= newcols)
		term->alt_x = newcols - 1;
	term->alt_x = term->alt_y = 0;
	term->wrapnext = term->alt_wnext = FALSE;

	term->rows = newrows;
	term->cols = newcols;
	term->savelines = newsavelines;

	swap_screen(term, save_alt_which, FALSE, FALSE);

	update_sbar(term);
	term_update(term);
	if (term->resize_fn)
		term->resize_fn(term->resize_ctx, term->cols, term->rows);
}

/*
* Hand a function and context pointer to the terminal which it can
* use to notify a back end of resizes.
*/
void term_provide_resize_fn(Terminal *term,
	void (*resize_fn)(void *, int, int),
	void *resize_ctx)
{
	term->resize_fn = resize_fn;
	term->resize_ctx = resize_ctx;
	if (resize_fn && term->cols > 0 && term->rows > 0)
		resize_fn(resize_ctx, term->cols, term->rows);
}

/* Find the bottom line on the screen that has any content.
* If only the top line has content, returns 0.
* If no lines have content, return -1.
*/ 
static int find_last_nonempty_line(Terminal * term, tree234 * screen)
{
	int i;
	for (i = count234(screen) - 1; i >= 0; i--) {
		termline *line = index234(screen, i);
		int j;
		for (j = 0; j < line->cols; j++)
			if (!termchars_equal(&line->chars[j], &term->erase_char))
				break;
		if (j != line->cols) break;
	}
	return i;
}

/*
* Swap screens. If `reset' is TRUE and we have been asked to
* switch to the alternate screen, we must bring most of its
* configuration from the main screen and erase the contents of the
* alternate screen completely. (This is even true if we're already
* on it! Blame xterm.)
*/
static void swap_screen(Terminal *term, int which, int reset, int keep_cur_pos)
{
	int t;
	pos tp;
	tree234 *ttr;

	if (!which)
		reset = FALSE;		       /* do no weird resetting if which==0 */

	if (which != term->alt_which) {
		term->alt_which = which;

		ttr = term->alt_screen;
		term->alt_screen = term->screen;
		term->screen = ttr;
		term->alt_sblines = find_last_nonempty_line(term, term->alt_screen) + 1;
		t = term->curs.x;
		if (!reset && !keep_cur_pos)
			term->curs.x = term->alt_x;
		term->alt_x = t;
		t = term->curs.y;
		if (!reset && !keep_cur_pos)
			term->curs.y = term->alt_y;
		term->alt_y = t;
		t = term->marg_t;
		if (!reset) term->marg_t = term->alt_t;
		term->alt_t = t;
		t = term->marg_b;
		if (!reset) term->marg_b = term->alt_b;
		term->alt_b = t;
		t = term->dec_om;
		if (!reset) term->dec_om = term->alt_om;
		term->alt_om = t;
		t = term->wrap;
		if (!reset) term->wrap = term->alt_wrap;
		term->alt_wrap = t;
		t = term->wrapnext;
		if (!reset) term->wrapnext = term->alt_wnext;
		term->alt_wnext = t;
		t = term->insert;
		if (!reset) term->insert = term->alt_ins;
		term->alt_ins = t;
		t = term->cset;
		if (!reset) term->cset = term->alt_cset;
		term->alt_cset = t;
		t = term->utf;
		if (!reset) term->utf = term->alt_utf;
		term->alt_utf = t;
		t = term->sco_acs;
		if (!reset) term->sco_acs = term->alt_sco_acs;
		term->alt_sco_acs = t;

		tp = term->savecurs;
		if (!reset && !keep_cur_pos)
			term->savecurs = term->alt_savecurs;
		term->alt_savecurs = tp;
		t = term->save_cset;
		if (!reset && !keep_cur_pos)
			term->save_cset = term->alt_save_cset;
		term->alt_save_cset = t;
		t = term->save_csattr;
		if (!reset && !keep_cur_pos)
			term->save_csattr = term->alt_save_csattr;
		term->alt_save_csattr = t;
		t = term->save_attr;
		if (!reset && !keep_cur_pos)
			term->save_attr = term->alt_save_attr;
		term->alt_save_attr = t;
		t = term->save_utf;
		if (!reset && !keep_cur_pos)
			term->save_utf = term->alt_save_utf;
		term->alt_save_utf = t;
		t = term->save_wnext;
		if (!reset && !keep_cur_pos)
			term->save_wnext = term->alt_save_wnext;
		term->alt_save_wnext = t;
		t = term->save_sco_acs;
		if (!reset && !keep_cur_pos)
			term->save_sco_acs = term->alt_save_sco_acs;
		term->alt_save_sco_acs = t;
	}

	if (reset && term->screen) {
		/*
		* Yes, this _is_ supposed to honour background-colour-erase.
		*/
		erase_lots(term, FALSE, TRUE, TRUE);
	}
}

/*
* Update the scroll bar.
*/
static void update_sbar(Terminal *term)
{
	int nscroll = sblines(term);
	set_sbar(term->frontend, nscroll + term->rows,
		nscroll + term->disptop, term->rows);
}

/*
* Check whether the region bounded by the two pointers intersects
* the scroll region, and de-select the on-screen selection if so.
*/
static void check_selection(Terminal *term, pos from, pos to)
{
	if (poslt(from, term->selend) && poslt(term->selstart, to))
		deselect(term);
}

/*
* Scroll the screen. (`lines' is +ve for scrolling forward, -ve
* for backward.) `sb' is TRUE if the scrolling is permitted to
* affect the scrollback buffer.
*/
static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
{
	termline *line;
	int i, seltop, scrollwinsize;
#ifdef OPTIMISE_SCROLL
	int olddisptop, shift;
#endif /* OPTIMISE_SCROLL */

	if (topline != 0 || term->alt_which != 0)
		sb = FALSE;

#ifdef OPTIMISE_SCROLL
	olddisptop = term->disptop;
	shift = lines;
#endif /* OPTIMISE_SCROLL */

	scrollwinsize = botline - topline + 1;

	if (lines < 0) {
		lines = -lines;
		if (lines > scrollwinsize)
			lines = scrollwinsize;
		while (lines-- > 0) {
			line = delpos234(term->screen, botline);
			resizeline(term, line, term->cols);
			for (i = 0; i < term->cols; i++)
				copy_termchar(line, i, &term->erase_char);
			line->lattr = LATTR_NORM;
			addpos234(term->screen, line, topline);

			if (term->selstart.y >= topline && term->selstart.y <= botline) {
				term->selstart.y++;
				if (term->selstart.y > botline) {
					term->selstart.y = botline + 1;
					term->selstart.x = 0;
				}
			}
			if (term->selend.y >= topline && term->selend.y <= botline) {
				term->selend.y++;
				if (term->selend.y > botline) {
					term->selend.y = botline + 1;
					term->selend.x = 0;
				}
			}
		}
	} else {
		if (lines > scrollwinsize)
			lines = scrollwinsize;
		while (lines-- > 0) {
			line = delpos234(term->screen, topline);
#ifdef TERM_CC_DIAGS
			cc_check(line);
#endif
			if (sb && term->savelines > 0) {
				int sblen = count234(term->scrollback);
				/*
				* We must add this line to the scrollback. We'll
				* remove a line from the top of the scrollback if
				* the scrollback is full.
				*/
				if (sblen == term->savelines) {
					unsigned char *cline;

					sblen--;
					cline = delpos234(term->scrollback, 0);
					sfree(cline);
				} else
					term->tempsblines += 1;

				addpos234(term->scrollback, compressline(line), sblen);

				/* now `line' itself can be reused as the bottom line */

				/*
				* If the user is currently looking at part of the
				* scrollback, and they haven't enabled any options
				* that are going to reset the scrollback as a
				* result of this movement, then the chances are
				* they'd like to keep looking at the same line. So
				* we move their viewpoint at the same rate as the
				* scroll, at least until their viewpoint hits the
				* top end of the scrollback buffer, at which point
				* we don't have the choice any more.
				* 
				* Thanks to Jan Holmen Holsten for the idea and
				* initial implementation.
				*/
				if (term->disptop > -term->savelines && term->disptop < 0)
					term->disptop--;
			}
			resizeline(term, line, term->cols);
			for (i = 0; i < term->cols; i++)
				copy_termchar(line, i, &term->erase_char);
			line->lattr = LATTR_NORM;
			addpos234(term->screen, line, botline);

			/*
			* If the selection endpoints move into the scrollback,
			* we keep them moving until they hit the top. However,
			* of course, if the line _hasn't_ moved into the
			* scrollback then we don't do this, and cut them off
			* at the top of the scroll region.
			* 
			* This applies to selstart and selend (for an existing
			* selection), and also selanchor (for one being
			* selected as we speak).
			*/
			seltop = sb ? -term->savelines : topline;

			if (term->selstate != NO_SELECTION) {
				if (term->selstart.y >= seltop &&
					term->selstart.y <= botline) {
						term->selstart.y--;
						if (term->selstart.y < seltop) {
							term->selstart.y = seltop;
							term->selstart.x = 0;
						}
				}
				if (term->selend.y >= seltop && term->selend.y <= botline) {
					term->selend.y--;
					if (term->selend.y < seltop) {
						term->selend.y = seltop;
						term->selend.x = 0;
					}
				}
				if (term->selanchor.y >= seltop &&
					term->selanchor.y <= botline) {
						term->selanchor.y--;
						if (term->selanchor.y < seltop) {
							term->selanchor.y = seltop;
							term->selanchor.x = 0;
						}
				}
			}
		}
	}
#ifdef OPTIMISE_SCROLL
	shift += term->disptop - olddisptop;
	if (shift < term->rows && shift > -term->rows && shift != 0)
		scroll_display(term, topline, botline, shift);
#endif /* OPTIMISE_SCROLL */
}

#ifdef OPTIMISE_SCROLL
/*
* Add a scroll of a region on the screen into the pending scroll list.
* `lines' is +ve for scrolling forward, -ve for backward.
*
* If the scroll is on the same area as the last scroll in the list,
* merge them.
*/
static void save_scroll(Terminal *term, int topline, int botline, int lines)
{
	struct scrollregion *newscroll;
	if (term->scrolltail &&
		term->scrolltail->topline == topline && 
		term->scrolltail->botline == botline) {
			term->scrolltail->lines += lines;
	} else {
		newscroll = snew(struct scrollregion);
		newscroll->topline = topline;
		newscroll->botline = botline;
		newscroll->lines = lines;
		newscroll->next = NULL;

		if (!term->scrollhead)
			term->scrollhead = newscroll;
		else
			term->scrolltail->next = newscroll;
		term->scrolltail = newscroll;
	}
}

/*
* Scroll the physical display, and our conception of it in disptext.
*/
static void scroll_display(Terminal *term, int topline, int botline, int lines)
{
	int distance, nlines, i, j;

	distance = lines > 0 ? lines : -lines;
	nlines = botline - topline + 1 - distance;
	if (lines > 0) {
		for (i = 0; i < nlines; i++)
			for (j = 0; j < term->cols; j++)
				copy_termchar(term->disptext[i], j,
				term->disptext[i+distance]->chars+j);
		if (term->dispcursy >= 0 &&
			term->dispcursy >= topline + distance &&
			term->dispcursy < topline + distance + nlines)
			term->dispcursy -= distance;
		for (i = 0; i < distance; i++)
			for (j = 0; j < term->cols; j++)
				term->disptext[nlines+i]->chars[j].attr |= ATTR_INVALID;
	} else {
		for (i = nlines; i-- ;)
			for (j = 0; j < term->cols; j++)
				copy_termchar(term->disptext[i+distance], j,
				term->disptext[i]->chars+j);
		if (term->dispcursy >= 0 &&
			term->dispcursy >= topline &&
			term->dispcursy < topline + nlines)
			term->dispcursy += distance;
		for (i = 0; i < distance; i++)
			for (j = 0; j < term->cols; j++)
				term->disptext[i]->chars[j].attr |= ATTR_INVALID;
	}
	save_scroll(term, topline, botline, lines);
}
#endif /* OPTIMISE_SCROLL */

/*
* Move the cursor to a given position, clipping at boundaries. We
* may or may not want to clip at the scroll margin: marg_clip is 0
* not to, 1 to disallow _passing_ the margins, and 2 to disallow
* even _being_ outside the margins.
*/
static void move(Terminal *term, int x, int y, int marg_clip)
{
	if (x < 0)
		x = 0;
	if (x >= term->cols)
		x = term->cols - 1;
	if (marg_clip) {
		if ((term->curs.y >= term->marg_t || marg_clip == 2) &&
			y < term->marg_t)
			y = term->marg_t;
		if ((term->curs.y <= term->marg_b || marg_clip == 2) &&
			y > term->marg_b)
			y = term->marg_b;
	}
	if (y < 0)
		y = 0;
	if (y >= term->rows)
		y = term->rows - 1;
	term->curs.x = x;
	term->curs.y = y;
	term->wrapnext = FALSE;
}

/*
* Save or restore the cursor and SGR mode.
*/
static void save_cursor(Terminal *term, int save)
{
	if (save) {
		term->savecurs = term->curs;
		term->save_attr = term->curr_attr;
		term->save_cset = term->cset;
		term->save_utf = term->utf;
		term->save_wnext = term->wrapnext;
		term->save_csattr = term->cset_attr[term->cset];
		term->save_sco_acs = term->sco_acs;
	} else {
		term->curs = term->savecurs;
		/* Make sure the window hasn't shrunk since the save */
		if (term->curs.x >= term->cols)
			term->curs.x = term->cols - 1;
		if (term->curs.y >= term->rows)
			term->curs.y = term->rows - 1;

		term->curr_attr = term->save_attr;
		term->cset = term->save_cset;
		term->utf = term->save_utf;
		term->wrapnext = term->save_wnext;
		/*
		* wrapnext might reset to False if the x position is no
		* longer at the rightmost edge.
		*/
		if (term->wrapnext && term->curs.x < term->cols-1)
			term->wrapnext = FALSE;
		term->cset_attr[term->cset] = term->save_csattr;
		term->sco_acs = term->save_sco_acs;
		set_erase_char(term);
	}
}

/*
* This function is called before doing _anything_ which affects
* only part of a line of text. It is used to mark the boundary
* between two character positions, and it indicates that some sort
* of effect is going to happen on only one side of that boundary.
* 
* The effect of this function is to check whether a CJK
* double-width character is straddling the boundary, and to remove
* it and replace it with two spaces if so. (Of course, one or
* other of those spaces is then likely to be replaced with
* something else again, as a result of whatever happens next.)
* 
* Also, if the boundary is at the right-hand _edge_ of the screen,
* it implies something deliberate is being done to the rightmost
* column position; hence we must clear LATTR_WRAPPED2.
* 
* The input to the function is the coordinates of the _second_
* character of the pair.
*/
static void check_boundary(Terminal *term, int x, int y)
{
	termline *ldata;

	/* Validate input coordinates, just in case. */
	if (x <= 0 || x > term->cols)
		return;

	ldata = scrlineptr(y);
	check_line_size(term, ldata);
	if (x == term->cols) {
		ldata->lattr &= ~LATTR_WRAPPED2;
	} else {
		if (ldata->chars[x].chr == UCSWIDE) {
			clear_cc(ldata, x-1);
			clear_cc(ldata, x);
			ldata->chars[x-1].chr = ' ' | CSET_ASCII;
			ldata->chars[x] = ldata->chars[x-1];
		}
	}
}

/*
* Erase a large portion of the screen: the whole screen, or the
* whole line, or parts thereof.
*/
static void erase_lots(Terminal *term,
	int line_only, int from_begin, int to_end)
{
	pos start, end;
	int erase_lattr;
	int erasing_lines_from_top = 0;

	if (line_only) {
		start.y = term->curs.y;
		start.x = 0;
		end.y = term->curs.y + 1;
		end.x = 0;
		erase_lattr = FALSE;
	} else {
		start.y = 0;
		start.x = 0;
		end.y = term->rows;
		end.x = 0;
		erase_lattr = TRUE;
	}
	if (!from_begin) {
		start = term->curs;
	}
	if (!to_end) {
		end = term->curs;
		incpos(end);
	}
	if (!from_begin || !to_end)
		check_boundary(term, term->curs.x, term->curs.y);
	check_selection(term, start, end);

	/* Clear screen also forces a full window redraw, just in case. */
	if (start.y == 0 && start.x == 0 && end.y == term->rows)
		term_invalidate(term);

	/* Lines scrolled away shouldn't be brought back on if the terminal
	* resizes. */
	if (start.y == 0 && start.x == 0 && end.x == 0 && erase_lattr)
		erasing_lines_from_top = 1;

	if (term->erase_to_scrollback && erasing_lines_from_top) {
		/* If it's a whole number of lines, starting at the top, and
		* we're fully erasing them, erase by scrolling and keep the
		* lines in the scrollback. */
		int scrolllines = end.y;
		if (end.y == term->rows) {
			/* Shrink until we find a non-empty row.*/
			scrolllines = find_last_nonempty_line(term, term->screen) + 1;
		}
		if (scrolllines > 0)
			scroll(term, 0, scrolllines - 1, scrolllines, TRUE);
	} else {
		termline *ldata = scrlineptr(start.y);
		while (poslt(start, end)) {
			check_line_size(term, ldata);
			if (start.x == term->cols) {
				if (!erase_lattr)
					ldata->lattr &= ~(LATTR_WRAPPED | LATTR_WRAPPED2);
				else
					ldata->lattr = LATTR_NORM;
			} else {
				copy_termchar(ldata, start.x, &term->erase_char);
			}
			if (incpos(start) && start.y < term->rows) {
				ldata = scrlineptr(start.y);
			}
		}
	}

	/* After an erase of lines from the top of the screen, we shouldn't
	* bring the lines back again if the terminal enlarges (since the user or
	* application has explicitly thrown them away). */
	if (erasing_lines_from_top && !(term->alt_which))
		term->tempsblines = 0;
}

/*
* Insert or delete characters within the current line. n is +ve if
* insertion is desired, and -ve for deletion.
*/
static void insch(Terminal *term, int n)
{
	int dir = (n < 0 ? -1 : +1);
	int m, j;
	pos eol;
	termline *ldata;

	n = (n < 0 ? -n : n);
	if (n > term->cols - term->curs.x)
		n = term->cols - term->curs.x;
	m = term->cols - term->curs.x - n;

	/*
	* We must de-highlight the selection if it overlaps any part of
	* the region affected by this operation, i.e. the region from the
	* current cursor position to end-of-line, _unless_ the entirety
	* of the selection is going to be moved to the left or right by
	* this operation but otherwise unchanged, in which case we can
	* simply move the highlight with the text.
	*/
	eol.y = term->curs.y;
	eol.x = term->cols;
	if (poslt(term->curs, term->selend) && poslt(term->selstart, eol)) {
		pos okstart = term->curs;
		pos okend = eol;
		if (dir > 0) {
			/* Insertion: n characters at EOL will be splatted. */
			okend.x -= n;
		} else {
			/* Deletion: n characters at cursor position will be splatted. */
			okstart.x += n;
		}
		if (posle(okstart, term->selstart) && posle(term->selend, okend)) {
			/* Selection is contained entirely in the interval
			* [okstart,okend), so we need only adjust the selection
			* bounds. */
			term->selstart.x += dir * n;
			term->selend.x += dir * n;
			assert(term->selstart.x >= term->curs.x);
			assert(term->selstart.x < term->cols);
			assert(term->selend.x > term->curs.x);
			assert(term->selend.x <= term->cols);
		} else {
			/* Selection is not wholly contained in that interval, so
			* we must unhighlight it. */
			deselect(term);
		}
	}

	check_boundary(term, term->curs.x, term->curs.y);
	if (dir < 0)
		check_boundary(term, term->curs.x + n, term->curs.y);
	ldata = scrlineptr(term->curs.y);
	if (dir < 0) {
		for (j = 0; j < m; j++)
			move_termchar(ldata,
			ldata->chars + term->curs.x + j,
			ldata->chars + term->curs.x + j + n);
		while (n--)
			copy_termchar(ldata, term->curs.x + m++, &term->erase_char);
	} else {
		for (j = m; j-- ;)
			move_termchar(ldata,
			ldata->chars + term->curs.x + j + n,
			ldata->chars + term->curs.x + j);
		while (n--)
			copy_termchar(ldata, term->curs.x + n, &term->erase_char);
	}
}

/*
* Toggle terminal mode `mode' to state `state'. (`query' indicates
* whether the mode is a DEC private one or a normal one.)
*/
static void toggle_mode(Terminal *term, int mode, int query, int state)
{
	if (query)
		switch (mode) {
		case 1:		       /* DECCKM: application cursor keys */
			term->app_cursor_keys = state;
			break;
		case 2:		       /* DECANM: VT52 mode */
			term->vt52_mode = !state;
			if (term->vt52_mode) {
				term->blink_is_real = FALSE;
				term->vt52_bold = FALSE;
			} else {
				term->blink_is_real = term->blinktext;
			}
			term_schedule_tblink(term);
			break;
		case 3:		       /* DECCOLM: 80/132 columns */
			deselect(term);
			if (!term->no_remote_resize)
				request_resize(term->frontend, state ? 132 : 80, term->rows);
			term->reset_132 = state;
			term->alt_t = term->marg_t = 0;
			term->alt_b = term->marg_b = term->rows - 1;
			move(term, 0, 0, 0);
			erase_lots(term, FALSE, TRUE, TRUE);
			break;
		case 5:		       /* DECSCNM: reverse video */
			/*
			* Toggle reverse video. If we receive an OFF within the
			* visual bell timeout period after an ON, we trigger an
			* effective visual bell, so that ESC[?5hESC[?5l will
			* always be an actually _visible_ visual bell.
			*/
			if (term->rvideo && !state) {
				/* This is an OFF, so set up a vbell */
				term_schedule_vbell(term, TRUE, term->rvbell_startpoint);
			} else if (!term->rvideo && state) {
				/* This is an ON, so we notice the time and save it. */
				term->rvbell_startpoint = GETTICKCOUNT();
			}
			term->rvideo = state;
			seen_disp_event(term);
			break;
		case 6:		       /* DECOM: DEC origin mode */
			term->dec_om = state;
			break;
		case 7:		       /* DECAWM: auto wrap */
			term->wrap = state;
			break;
		case 8:		       /* DECARM: auto key repeat */
			term->repeat_off = !state;
			break;
		case 10:		       /* DECEDM: set local edit mode */
			term->term_editing = state;
			if (term->ldisc)	       /* cause ldisc to notice changes */
				ldisc_echoedit_update(term->ldisc);
			break;
		case 25:		       /* DECTCEM: enable/disable cursor */
			compatibility2(OTHER, VT220);
			term->cursor_on = state;
			seen_disp_event(term);
			break;
		case 47:		       /* alternate screen */
			compatibility(OTHER);
			deselect(term);
			swap_screen(term, term->no_alt_screen ? 0 : state, FALSE, FALSE);
			if (term->scroll_on_disp)
				term->disptop = 0;
			break;
		case 1000:		       /* xterm mouse 1 (normal) */
			term->xterm_mouse = state ? 1 : 0;
			set_raw_mouse_mode(term->frontend, state);
			break;
		case 1002:		       /* xterm mouse 2 (inc. button drags) */
			term->xterm_mouse = state ? 2 : 0;
			set_raw_mouse_mode(term->frontend, state);
			break;
		case 1006:		       /* xterm extended mouse */
			term->xterm_extended_mouse = state ? 1 : 0;
			break;
		case 1015:		       /* urxvt extended mouse */
			term->urxvt_extended_mouse = state ? 1 : 0;
			break;
		case 1047:                   /* alternate screen */
			compatibility(OTHER);
			deselect(term);
			swap_screen(term, term->no_alt_screen ? 0 : state, TRUE, TRUE);
			if (term->scroll_on_disp)
				term->disptop = 0;
			break;
		case 1048:                   /* save/restore cursor */
			if (!term->no_alt_screen)
				save_cursor(term, state);
			if (!state) seen_disp_event(term);
			break;
		case 1049:                   /* cursor & alternate screen */
			if (state && !term->no_alt_screen)
				save_cursor(term, state);
			if (!state) seen_disp_event(term);
			compatibility(OTHER);
			deselect(term);
			swap_screen(term, term->no_alt_screen ? 0 : state, TRUE, FALSE);
			if (!state && !term->no_alt_screen)
				save_cursor(term, state);
			if (term->scroll_on_disp)
				term->disptop = 0;
			break;
		case 2004:		       /* xterm bracketed paste */
			term->bracketed_paste = state ? TRUE : FALSE;
			break;
	} else
		switch (mode) {
		case 4:		       /* IRM: set insert mode */
			compatibility(VT102);
			term->insert = state;
			break;
		case 12:		       /* SRM: set echo mode */
			term->term_echoing = !state;
			if (term->ldisc)	       /* cause ldisc to notice changes */
				ldisc_echoedit_update(term->ldisc);
			break;
		case 20:		       /* LNM: Return sends ... */
			term->cr_lf_return = state;
			break;
		case 34:		       /* WYULCURM: Make cursor BIG */
			compatibility2(OTHER, VT220);
			term->big_cursor = !state;
	}
}

/*
* Process an OSC sequence: set window title or icon name.
*/
static void do_osc(Terminal *term)
{
	if (term->osc_w) {
		while (term->osc_strlen--)
			term->wordness[(unsigned char)
			term->osc_string[term->osc_strlen]] = term->esc_args[0];
	} else {
		term->osc_string[term->osc_strlen] = '\0';
		switch (term->esc_args[0]) {
		case 0:
		case 1:
			if (!term->no_remote_wintitle)
				set_icon(term->frontend, term->osc_string);
			if (term->esc_args[0] == 1)
				break;
			/* fall through: parameter 0 means set both */
		case 2:
		case 21:
			if (!term->no_remote_wintitle)
				set_title(term->frontend, term->osc_string);
			break;
		}
	}
}

/*
* ANSI printing routines.
*/
static void term_print_setup(Terminal *term, char *printer)
{
	bufchain_clear(&term->printer_buf);
	term->print_job = printer_start_job(printer);
}
static void term_print_flush(Terminal *term)
{
	void *data;
	int len;
	int size;
	while ((size = bufchain_size(&term->printer_buf)) > 5) {
		bufchain_prefix(&term->printer_buf, &data, &len);
		if (len > size-5)
			len = size-5;
		printer_job_data(term->print_job, data, len);
		bufchain_consume(&term->printer_buf, len);
	}
}
static void term_print_finish(Terminal *term)
{
	void *data;
	int len, size;
	char c;

	if (!term->printing && !term->only_printing)
		return;			       /* we need do nothing */

	term_print_flush(term);
	while ((size = bufchain_size(&term->printer_buf)) > 0) {
		bufchain_prefix(&term->printer_buf, &data, &len);
		c = *(char *)data;
		if (c == '\033' || c == '\233') {
			bufchain_consume(&term->printer_buf, size);
			break;
		} else {
			printer_job_data(term->print_job, &c, 1);
			bufchain_consume(&term->printer_buf, 1);
		}
	}
	printer_finish_job(term->print_job);
	term->print_job = NULL;
	term->printing = term->only_printing = FALSE;
}

/*
* Remove everything currently in `inbuf' and stick it up on the
* in-memory display. There's a big state machine in here to
* process escape sequences...
*/
static void term_out(Terminal *term)
{
	unsigned long c;
	int unget;
	unsigned char localbuf[256], *chars;
	int nchars = 0;

	unget = -1;

	chars = NULL;		       /* placate compiler warnings */
	while (nchars > 0 || unget != -1 || bufchain_size(&term->inbuf) > 0) {
		if (unget == -1) {
			if (nchars == 0) {
				void *ret;
				bufchain_prefix(&term->inbuf, &ret, &nchars);
				if (nchars > sizeof(localbuf))
					nchars = sizeof(localbuf);
				memcpy(localbuf, ret, nchars);
				bufchain_consume(&term->inbuf, nchars);
				chars = localbuf;
				assert(chars != NULL);
			}
			c = *chars++;
			nchars--;

			/*
			* Optionally log the session traffic to a file. Useful for
			* debugging and possibly also useful for actual logging.
			*/
			if (term->logtype == LGTYP_DEBUG && term->logctx)
				logtraffic(term->logctx, (unsigned char) c, LGTYP_DEBUG);
		} else {
			c = unget;
			unget = -1;
		}

		/* Note only VT220+ are 8-bit VT102 is seven bit, it shouldn't even
		* be able to display 8-bit characters, but I'll let that go 'cause
		* of i18n.
		*/

		/*
		* If we're printing, add the character to the printer
		* buffer.
		*/
		if (term->printing) {
			bufchain_add(&term->printer_buf, &c, 1);

			/*
			* If we're in print-only mode, we use a much simpler
			* state machine designed only to recognise the ESC[4i
			* termination sequence.
			*/
			if (term->only_printing) {
				if (c == '\033')
					term->print_state = 1;
				else if (c == (unsigned char)'\233')
					term->print_state = 2;
				else if (c == '[' && term->print_state == 1)
					term->print_state = 2;
				else if (c == '4' && term->print_state == 2)
					term->print_state = 3;
				else if (c == 'i' && term->print_state == 3)
					term->print_state = 4;
				else
					term->print_state = 0;
				if (term->print_state == 4) {
					term_print_finish(term);
				}
				continue;
			}
		}

		/* First see about all those translations. */
		if (term->termstate == TOPLEVEL) {
			if (in_utf(term))
				switch (term->utf_state) {
				case 0:
					if (c < 0x80) {
						/* UTF-8 must be stateless so we ignore iso2022. */
						if (term->ucsdata->unitab_ctrl[c] != 0xFF) 
							c = term->ucsdata->unitab_ctrl[c];
						else c = ((unsigned char)c) | CSET_ASCII;
						break;
					} else if ((c & 0xe0) == 0xc0) {
						term->utf_size = term->utf_state = 1;
						term->utf_char = (c & 0x1f);
					} else if ((c & 0xf0) == 0xe0) {
						term->utf_size = term->utf_state = 2;
						term->utf_char = (c & 0x0f);
					} else if ((c & 0xf8) == 0xf0) {
						term->utf_size = term->utf_state = 3;
						term->utf_char = (c & 0x07);
					} else if ((c & 0xfc) == 0xf8) {
						term->utf_size = term->utf_state = 4;
						term->utf_char = (c & 0x03);
					} else if ((c & 0xfe) == 0xfc) {
						term->utf_size = term->utf_state = 5;
						term->utf_char = (c & 0x01);
					} else {
						c = UCSERR;
						break;
					}
					continue;
				case 1:
				case 2:
				case 3:
				case 4:
				case 5:
					if ((c & 0xC0) != 0x80) {
						unget = c;
						c = UCSERR;
						term->utf_state = 0;
						break;
					}
					term->utf_char = (term->utf_char << 6) | (c & 0x3f);
					if (--term->utf_state)
						continue;

					c = term->utf_char;

					/* Is somebody trying to be evil! */
					if (c < 0x80 ||
						(c < 0x800 && term->utf_size >= 2) ||
						(c < 0x10000 && term->utf_size >= 3) ||
						(c < 0x200000 && term->utf_size >= 4) ||
						(c < 0x4000000 && term->utf_size >= 5))
						c = UCSERR;

					/* Unicode line separator and paragraph separator are CR-LF */
					if (c == 0x2028 || c == 0x2029)
						c = 0x85;

					/* High controls are probably a Baaad idea too. */
					if (c < 0xA0)
						c = 0xFFFD;

					/* The UTF-16 surrogates are not nice either. */
					/*       The standard give the option of decoding these: 
					*       I don't want to! */
					if (c >= 0xD800 && c < 0xE000)
						c = UCSERR;

					/* ISO 10646 characters now limited to UTF-16 range. */
					if (c > 0x10FFFF)
						c = UCSERR;

					/* This is currently a TagPhobic application.. */
					if (c >= 0xE0000 && c <= 0xE007F)
						continue;

					/* U+FEFF is best seen as a null. */
					if (c == 0xFEFF)
						continue;
					/* But U+FFFE is an error. */
					if (c == 0xFFFE || c == 0xFFFF)
						c = UCSERR;

					break;
			}
			/* Are we in the nasty ACS mode? Note: no sco in utf mode. */
			else if(term->sco_acs && 
				(c!='\033' && c!='\012' && c!='\015' && c!='\b'))
			{
				if (term->sco_acs == 2) c |= 0x80;
				c |= CSET_SCOACS;
			} else {
				switch (term->cset_attr[term->cset]) {
					/* 
					* Linedraw characters are different from 'ESC ( B'
					* only for a small range. For ones outside that
					* range, make sure we use the same font as well as
					* the same encoding.
					*/
				case CSET_LINEDRW:
					if (term->ucsdata->unitab_ctrl[c] != 0xFF)
						c = term->ucsdata->unitab_ctrl[c];
					else
						c = ((unsigned char) c) | CSET_LINEDRW;
					break;

				case CSET_GBCHR:
					/* If UK-ASCII, make the '#' a LineDraw Pound */
					if (c == '#') {
						c = '}' | CSET_LINEDRW;
						break;
					}
					/*FALLTHROUGH*/ case CSET_ASCII:
						if (term->ucsdata->unitab_ctrl[c] != 0xFF)
							c = term->ucsdata->unitab_ctrl[c];
						else
							c = ((unsigned char) c) | CSET_ASCII;
						break;
					case CSET_SCOACS:
						if (c>=' ') c = ((unsigned char)c) | CSET_SCOACS;
						break;
				}
			}
		}

		/*
		* How about C1 controls? 
		* Explicitly ignore SCI (0x9a), which we don't translate to DECID.
		*/
		if ((c & -32) == 0x80 && term->termstate < DO_CTRLS &&
			!term->vt52_mode && has_compat(VT220)) {
				if (c == 0x9a)
					c = 0;
				else {
					term->termstate = SEEN_ESC;
					term->esc_query = FALSE;
					c = '@' + (c & 0x1F);
				}
		}

		/* Or the GL control. */
		if (c == '\177' && term->termstate < DO_CTRLS && has_compat(OTHER)) {
			if (term->curs.x && !term->wrapnext)
				term->curs.x--;
			term->wrapnext = FALSE;
			/* destructive backspace might be disabled */
			if (!term->no_dbackspace) {
				check_boundary(term, term->curs.x, term->curs.y);
				check_boundary(term, term->curs.x+1, term->curs.y);
				copy_termchar(scrlineptr(term->curs.y),
					term->curs.x, &term->erase_char);
			}
		} else
			/* Or normal C0 controls. */
			if ((c & ~0x1F) == 0 && term->termstate < DO_CTRLS) {
				switch (c) {
				case '\005':	       /* ENQ: terminal type query */
					/* 
					* Strictly speaking this is VT100 but a VT100 defaults to
					* no response. Other terminals respond at their option.
					*
					* Don't put a CR in the default string as this tends to
					* upset some weird software.
					*/
					compatibility(ANSIMIN);
					if (term->ldisc) {
						lpage_send(term->ldisc, DEFAULT_CODEPAGE,
							term->answerback, term->answerbacklen, 0);
					}
					break;
				case '\007':	      /* BEL: Bell */
					{
						struct beeptime *newbeep;
						unsigned long ticks;

						ticks = GETTICKCOUNT();

						if (!term->beep_overloaded) {
							newbeep = snew(struct beeptime);
							newbeep->ticks = ticks;
							newbeep->next = NULL;
							if (!term->beephead)
								term->beephead = newbeep;
							else
								term->beeptail->next = newbeep;
							term->beeptail = newbeep;
							term->nbeeps++;
						}

						/*
						* Throw out any beeps that happened more than
						* t seconds ago.
						*/
						while (term->beephead &&
							term->beephead->ticks < ticks - term->bellovl_t) {
								struct beeptime *tmp = term->beephead;
								term->beephead = tmp->next;
								sfree(tmp);
								if (!term->beephead)
									term->beeptail = NULL;
								term->nbeeps--;
						}

						if (term->bellovl && term->beep_overloaded &&
							ticks - term->lastbeep >= (unsigned)term->bellovl_s) {
								/*
								* If we're currently overloaded and the
								* last beep was more than s seconds ago,
								* leave overload mode.
								*/
								term->beep_overloaded = FALSE;
						} else if (term->bellovl && !term->beep_overloaded &&
							term->nbeeps >= term->bellovl_n) {
								/*
								* Now, if we have n or more beeps
								* remaining in the queue, go into overload
								* mode.
								*/
								term->beep_overloaded = TRUE;
						}
						term->lastbeep = ticks;

						/*
						* Perform an actual beep if we're not overloaded.
						*/
						if (!term->bellovl || !term->beep_overloaded) {
							do_beep(term->frontend, term->beep);

							if (term->beep == BELL_VISUAL) {
								term_schedule_vbell(term, FALSE, 0);
							}
						}
						seen_disp_event(term);
					}
					break;
				case '\b':	      /* BS: Back space */
					if (term->curs.x == 0 &&
						(term->curs.y == 0 || term->wrap == 0))
						/* do nothing */ ;
					else if (term->curs.x == 0 && term->curs.y > 0)
						term->curs.x = term->cols - 1, term->curs.y--;
					else if (term->wrapnext)
						term->wrapnext = FALSE;
					else
						term->curs.x--;
					seen_disp_event(term);
					break;
				case '\016':	      /* LS1: Locking-shift one */
					compatibility(VT100);
					term->cset = 1;
					break;
				case '\017':	      /* LS0: Locking-shift zero */
					compatibility(VT100);
					term->cset = 0;
					break;
				case '\033':	      /* ESC: Escape */
					if (term->vt52_mode)
						term->termstate = VT52_ESC;
					else {
						compatibility(ANSIMIN);
						term->termstate = SEEN_ESC;
						term->esc_query = FALSE;
					}
					break;
				case '\015':	      /* CR: Carriage return */
					term->curs.x = 0;
					term->wrapnext = FALSE;
					seen_disp_event(term);

					if (term->crhaslf) {
						if (term->curs.y == term->marg_b)
							scroll(term, term->marg_t, term->marg_b, 1, TRUE);
						else if (term->curs.y < term->rows - 1)
							term->curs.y++;
					}
					if (term->logctx)
						logtraffic(term->logctx, (unsigned char) c, LGTYP_ASCII);
					break;
				case '\014':	      /* FF: Form feed */
					if (has_compat(SCOANSI)) {
						move(term, 0, 0, 0);
						erase_lots(term, FALSE, FALSE, TRUE);
						if (term->scroll_on_disp)
							term->disptop = 0;
						term->wrapnext = FALSE;
						seen_disp_event(term);
						break;
					}
				case '\013':	      /* VT: Line tabulation */
					compatibility(VT100);
				case '\012':	      /* LF: Line feed */
					if (term->curs.y == term->marg_b)
						scroll(term, term->marg_t, term->marg_b, 1, TRUE);
					else if (term->curs.y < term->rows - 1)
						term->curs.y++;
					if (term->lfhascr)
						term->curs.x = 0;
					term->wrapnext = FALSE;
					seen_disp_event(term);
					if (term->logctx)
						logtraffic(term->logctx, (unsigned char) c, LGTYP_ASCII);
					break;
				case '\t':	      /* HT: Character tabulation */
					{
						pos old_curs = term->curs;
						termline *ldata = scrlineptr(term->curs.y);

						do {
							term->curs.x++;
						} while (term->curs.x < term->cols - 1 &&
							!term->tabs[term->curs.x]);

						if ((ldata->lattr & LATTR_MODE) != LATTR_NORM) {
							if (term->curs.x >= term->cols / 2)
								term->curs.x = term->cols / 2 - 1;
						} else {
							if (term->curs.x >= term->cols)
								term->curs.x = term->cols - 1;
						}

						check_selection(term, old_curs, term->curs);
					}
					seen_disp_event(term);
					break;
				}
			} else
				switch (term->termstate) {
				case TOPLEVEL:
					/* Only graphic characters get this far;
					* ctrls are stripped above */
					{
						termline *cline = scrlineptr(term->curs.y);
						int width = 0;
						if (DIRECT_CHAR(c))
							width = 1;
						if (!width)
							width = (term->cjk_ambig_wide ?
							mk_wcwidth_cjk((unsigned int) c) :
						mk_wcwidth((unsigned int) c));

						if (term->wrapnext && term->wrap && width > 0) {
							cline->lattr |= LATTR_WRAPPED;
							if (term->curs.y == term->marg_b)
								scroll(term, term->marg_t, term->marg_b, 1, TRUE);
							else if (term->curs.y < term->rows - 1)
								term->curs.y++;
							term->curs.x = 0;
							term->wrapnext = FALSE;
							cline = scrlineptr(term->curs.y);
						}
						if (term->insert && width > 0)
							insch(term, width);
						if (term->selstate != NO_SELECTION) {
							pos cursplus = term->curs;
							incpos(cursplus);
							check_selection(term, term->curs, cursplus);
						}
						if (((c & CSET_MASK) == CSET_ASCII ||
							(c & CSET_MASK) == 0) &&
							term->logctx)
							logtraffic(term->logctx, (unsigned char) c,
							LGTYP_ASCII);

						switch (width) {
						case 2:
							/*
							* If we're about to display a double-width
							* character starting in the rightmost
							* column, then we do something special
							* instead. We must print a space in the
							* last column of the screen, then wrap;
							* and we also set LATTR_WRAPPED2 which
							* instructs subsequent cut-and-pasting not
							* only to splice this line to the one
							* after it, but to ignore the space in the
							* last character position as well.
							* (Because what was actually output to the
							* terminal was presumably just a sequence
							* of CJK characters, and we don't want a
							* space to be pasted in the middle of
							* those just because they had the
							* misfortune to start in the wrong parity
							* column. xterm concurs.)
							*/
							check_boundary(term, term->curs.x, term->curs.y);
							check_boundary(term, term->curs.x+2, term->curs.y);
							if (term->curs.x == term->cols-1) {
								copy_termchar(cline, term->curs.x,
									&term->erase_char);
								cline->lattr |= LATTR_WRAPPED | LATTR_WRAPPED2;
								if (term->curs.y == term->marg_b)
									scroll(term, term->marg_t, term->marg_b,
									1, TRUE);
								else if (term->curs.y < term->rows - 1)
									term->curs.y++;
								term->curs.x = 0;
								cline = scrlineptr(term->curs.y);
								/* Now we must check_boundary again, of course. */
								check_boundary(term, term->curs.x, term->curs.y);
								check_boundary(term, term->curs.x+2, term->curs.y);
							}

							/* FULL-TERMCHAR */
							clear_cc(cline, term->curs.x);
							cline->chars[term->curs.x].chr = c;
							cline->chars[term->curs.x].attr = term->curr_attr;

							term->curs.x++;

							/* FULL-TERMCHAR */
							clear_cc(cline, term->curs.x);
							cline->chars[term->curs.x].chr = UCSWIDE;
							cline->chars[term->curs.x].attr = term->curr_attr;

							break;
						case 1:
							check_boundary(term, term->curs.x, term->curs.y);
							check_boundary(term, term->curs.x+1, term->curs.y);

							/* FULL-TERMCHAR */
							clear_cc(cline, term->curs.x);
							cline->chars[term->curs.x].chr = c;
							cline->chars[term->curs.x].attr = term->curr_attr;

							break;
						case 0:
							if (term->curs.x > 0) {
								int x = term->curs.x - 1;

								/* If we're in wrapnext state, the character
								* to combine with is _here_, not to our left. */
								if (term->wrapnext)
									x++;

								/*
								* If the previous character is
								* UCSWIDE, back up another one.
								*/
								if (cline->chars[x].chr == UCSWIDE) {
									assert(x > 0);
									x--;
								}

								add_cc(cline, x, c);
								seen_disp_event(term);
							}
							continue;
						default:
							continue;
						}
						term->curs.x++;
						if (term->curs.x == term->cols) {
							term->curs.x--;
							term->wrapnext = TRUE;
							if (term->wrap && term->vt52_mode) {
								cline->lattr |= LATTR_WRAPPED;
								if (term->curs.y == term->marg_b)
									scroll(term, term->marg_t, term->marg_b, 1, TRUE);
								else if (term->curs.y < term->rows - 1)
									term->curs.y++;
								term->curs.x = 0;
								term->wrapnext = FALSE;
							}
						}
						seen_disp_event(term);
					}
					break;

				case OSC_MAYBE_ST:
					/*
					* This state is virtually identical to SEEN_ESC, with the
					* exception that we have an OSC sequence in the pipeline,
					* and _if_ we see a backslash, we process it.
					*/
					if (c == '\\') {
						do_osc(term);
						term->termstate = TOPLEVEL;
						break;
					}
					/* else fall through */
				case SEEN_ESC:
					if (c >= ' ' && c <= '/') {
						if (term->esc_query)
							term->esc_query = -1;
						else
							term->esc_query = c;
						break;
					}
					term->termstate = TOPLEVEL;
					switch (ANSI(c, term->esc_query)) {
					case '[':		/* enter CSI mode */
						term->termstate = SEEN_CSI;
						term->esc_nargs = 1;
						term->esc_args[0] = ARG_DEFAULT;
						term->esc_query = FALSE;
						break;
					case ']':		/* OSC: xterm escape sequences */
						/* Compatibility is nasty here, xterm, linux, decterm yuk! */
						compatibility(OTHER);
						term->termstate = SEEN_OSC;
						term->esc_args[0] = 0;
						break;
					case '7':		/* DECSC: save cursor */
						compatibility(VT100);
						save_cursor(term, TRUE);
						break;
					case '8':	 	/* DECRC: restore cursor */
						compatibility(VT100);
						save_cursor(term, FALSE);
						seen_disp_event(term);
						break;
					case '=':		/* DECKPAM: Keypad application mode */
						compatibility(VT100);
						term->app_keypad_keys = TRUE;
						break;
					case '>':		/* DECKPNM: Keypad numeric mode */
						compatibility(VT100);
						term->app_keypad_keys = FALSE;
						break;
					case 'D':	       /* IND: exactly equivalent to LF */
						compatibility(VT100);
						if (term->curs.y == term->marg_b)
							scroll(term, term->marg_t, term->marg_b, 1, TRUE);
						else if (term->curs.y < term->rows - 1)
							term->curs.y++;
						term->wrapnext = FALSE;
						seen_disp_event(term);
						break;
					case 'E':	       /* NEL: exactly equivalent to CR-LF */
						compatibility(VT100);
						term->curs.x = 0;
						if (term->curs.y == term->marg_b)
							scroll(term, term->marg_t, term->marg_b, 1, TRUE);
						else if (term->curs.y < term->rows - 1)
							term->curs.y++;
						term->wrapnext = FALSE;
						seen_disp_event(term);
						break;
					case 'M':	       /* RI: reverse index - backwards LF */
						compatibility(VT100);
						if (term->curs.y == term->marg_t)
							scroll(term, term->marg_t, term->marg_b, -1, TRUE);
						else if (term->curs.y > 0)
							term->curs.y--;
						term->wrapnext = FALSE;
						seen_disp_event(term);
						break;
					case 'Z':	       /* DECID: terminal type query */
						compatibility(VT100);
						if (term->ldisc)
							ldisc_send(term->ldisc, term->id_string,
							strlen(term->id_string), 0);
						break;
					case 'c':	       /* RIS: restore power-on settings */
						compatibility(VT100);
						power_on(term, TRUE);
						if (term->ldisc)   /* cause ldisc to notice changes */
							ldisc_echoedit_update(term->ldisc);
						if (term->reset_132) {
							if (!term->no_remote_resize)
								request_resize(term->frontend, 80, term->rows);
							term->reset_132 = 0;
						}
						if (term->scroll_on_disp)
							term->disptop = 0;
						seen_disp_event(term);
						break;
					case 'H':	       /* HTS: set a tab */
						compatibility(VT100);
						term->tabs[term->curs.x] = TRUE;
						break;

					case ANSI('8', '#'):	/* DECALN: fills screen with Es :-) */
						compatibility(VT100);
						{
							termline *ldata;
							int i, j;
							pos scrtop, scrbot;

							for (i = 0; i < term->rows; i++) {
								ldata = scrlineptr(i);
								check_line_size(term, ldata);
								for (j = 0; j < term->cols; j++) {
									copy_termchar(ldata, j,
										&term->basic_erase_char);
									ldata->chars[j].chr = 'E';
								}
								ldata->lattr = LATTR_NORM;
							}
							if (term->scroll_on_disp)
								term->disptop = 0;
							seen_disp_event(term);
							scrtop.x = scrtop.y = 0;
							scrbot.x = 0;
							scrbot.y = term->rows;
							check_selection(term, scrtop, scrbot);
						}
						break;

					case ANSI('3', '#'):
					case ANSI('4', '#'):
					case ANSI('5', '#'):
					case ANSI('6', '#'):
						compatibility(VT100);
						{
							int nlattr;
							termline *ldata;

							switch (ANSI(c, term->esc_query)) {
							case ANSI('3', '#'): /* DECDHL: 2*height, top */
								nlattr = LATTR_TOP;
								break;
							case ANSI('4', '#'): /* DECDHL: 2*height, bottom */
								nlattr = LATTR_BOT;
								break;
							case ANSI('5', '#'): /* DECSWL: normal */
								nlattr = LATTR_NORM;
								break;
							default: /* case ANSI('6', '#'): DECDWL: 2*width */
								nlattr = LATTR_WIDE;
								break;
							}
							ldata = scrlineptr(term->curs.y);
							check_line_size(term, ldata);
							ldata->lattr = nlattr;
						}
						break;
						/* GZD4: G0 designate 94-set */
					case ANSI('A', '('):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[0] = CSET_GBCHR;
						break;
					case ANSI('B', '('):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[0] = CSET_ASCII;
						break;
					case ANSI('0', '('):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[0] = CSET_LINEDRW;
						break;
					case ANSI('U', '('): 
						compatibility(OTHER);
						if (!term->no_remote_charset)
							term->cset_attr[0] = CSET_SCOACS; 
						break;
						/* G1D4: G1-designate 94-set */
					case ANSI('A', ')'):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[1] = CSET_GBCHR;
						break;
					case ANSI('B', ')'):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[1] = CSET_ASCII;
						break;
					case ANSI('0', ')'):
						compatibility(VT100);
						if (!term->no_remote_charset)
							term->cset_attr[1] = CSET_LINEDRW;
						break;
					case ANSI('U', ')'): 
						compatibility(OTHER);
						if (!term->no_remote_charset)
							term->cset_attr[1] = CSET_SCOACS; 
						break;
						/* DOCS: Designate other coding system */
					case ANSI('8', '%'):	/* Old Linux code */
					case ANSI('G', '%'):
						compatibility(OTHER);
						if (!term->no_remote_charset)
							term->utf = 1;
						break;
					case ANSI('@', '%'):
						compatibility(OTHER);
						if (!term->no_remote_charset)
							term->utf = 0;
						break;
					}
					break;
				case SEEN_CSI:
					term->termstate = TOPLEVEL;  /* default */
					if (isdigit(c)) {
						if (term->esc_nargs <= ARGS_MAX) {
							if (term->esc_args[term->esc_nargs - 1] == ARG_DEFAULT)
								term->esc_args[term->esc_nargs - 1] = 0;
							if (term->esc_args[term->esc_nargs - 1] <=
								UINT_MAX / 10 &&
								term->esc_args[term->esc_nargs - 1] * 10 <=
								UINT_MAX - c - '0')
								term->esc_args[term->esc_nargs - 1] =
								10 * term->esc_args[term->esc_nargs - 1] +
								c - '0';
							else
								term->esc_args[term->esc_nargs - 1] = UINT_MAX;
						}
						term->termstate = SEEN_CSI;
					} else if (c == ';') {
						if (term->esc_nargs < ARGS_MAX)
							term->esc_args[term->esc_nargs++] = ARG_DEFAULT;
						term->termstate = SEEN_CSI;
					} else if (c < '@') {
						if (term->esc_query)
							term->esc_query = -1;
						else if (c == '?')
							term->esc_query = TRUE;
						else
							term->esc_query = c;
						term->termstate = SEEN_CSI;
					} else
#define CLAMP(arg, lim) ((arg) = ((arg) > (lim)) ? (lim) : (arg))
						switch (ANSI(c, term->esc_query)) {
						case 'A':       /* CUU: move up N lines */
							CLAMP(term->esc_args[0], term->rows);
							move(term, term->curs.x,
								term->curs.y - def(term->esc_args[0], 1), 1);
							seen_disp_event(term);
							break;
						case 'e':		/* VPR: move down N lines */
							compatibility(ANSI);
							/* FALLTHROUGH */
						case 'B':		/* CUD: Cursor down */
							CLAMP(term->esc_args[0], term->rows);
							move(term, term->curs.x,
								term->curs.y + def(term->esc_args[0], 1), 1);
							seen_disp_event(term);
							break;
						case ANSI('c', '>'):	/* DA: report xterm version */
							compatibility(OTHER);
							/* this reports xterm version 136 so that VIM can
							use the drag messages from the mouse reporting */
							if (term->ldisc)
								ldisc_send(term->ldisc, "\033[>0;136;0c", 11, 0);
							break;
						case 'a':		/* HPR: move right N cols */
							compatibility(ANSI);
							/* FALLTHROUGH */
						case 'C':		/* CUF: Cursor right */ 
							CLAMP(term->esc_args[0], term->cols);
							move(term, term->curs.x + def(term->esc_args[0], 1),
								term->curs.y, 1);
							seen_disp_event(term);
							break;
						case 'D':       /* CUB: move left N cols */
							CLAMP(term->esc_args[0], term->cols);
							move(term, term->curs.x - def(term->esc_args[0], 1),
								term->curs.y, 1);
							seen_disp_event(term);
							break;
						case 'E':       /* CNL: move down N lines and CR */
							compatibility(ANSI);
							CLAMP(term->esc_args[0], term->rows);
							move(term, 0,
								term->curs.y + def(term->esc_args[0], 1), 1);
							seen_disp_event(term);
							break;
						case 'F':       /* CPL: move up N lines and CR */
							compatibility(ANSI);
							CLAMP(term->esc_args[0], term->rows);
							move(term, 0,
								term->curs.y - def(term->esc_args[0], 1), 1);
							seen_disp_event(term);
							break;
						case 'G':	      /* CHA */
						case '`':       /* HPA: set horizontal posn */
							compatibility(ANSI);
							CLAMP(term->esc_args[0], term->cols);
							move(term, def(term->esc_args[0], 1) - 1,
								term->curs.y, 0);
							seen_disp_event(term);
							break;
						case 'd':       /* VPA: set vertical posn */
							compatibility(ANSI);
							CLAMP(term->esc_args[0], term->rows);
							move(term, term->curs.x,
								((term->dec_om ? term->marg_t : 0) +
								def(term->esc_args[0], 1) - 1),
								(term->dec_om ? 2 : 0));
							seen_disp_event(term);
							break;
						case 'H':	     /* CUP */
						case 'f':      /* HVP: set horz and vert posns at once */
							if (term->esc_nargs < 2)
								term->esc_args[1] = ARG_DEFAULT;
							CLAMP(term->esc_args[0], term->rows);
							CLAMP(term->esc_args[1], term->cols);
							move(term, def(term->esc_args[1], 1) - 1,
								((term->dec_om ? term->marg_t : 0) +
								def(term->esc_args[0], 1) - 1),
								(term->dec_om ? 2 : 0));
							seen_disp_event(term);
							break;
						case 'J':       /* ED: erase screen or parts of it */
							{
								unsigned int i = def(term->esc_args[0], 0);
								if (i == 3) {
									/* Erase Saved Lines (xterm)
									* This follows Thomas Dickey's xterm. */
									if (!term->no_remote_clearscroll)
										term_clrsb(term);
								} else {
									i++;
									if (i > 3)
										i = 0;
									erase_lots(term, FALSE, !!(i & 2), !!(i & 1));
								}
							}
							if (term->scroll_on_disp)
								term->disptop = 0;
							seen_disp_event(term);
							break;
						case 'K':       /* EL: erase line or parts of it */
							{
								unsigned int i = def(term->esc_args[0], 0) + 1;
								if (i > 3)
									i = 0;
								erase_lots(term, TRUE, !!(i & 2), !!(i & 1));
							}
							seen_disp_event(term);
							break;
						case 'L':       /* IL: insert lines */
							compatibility(VT102);
							CLAMP(term->esc_args[0], term->rows);
							if (term->curs.y <= term->marg_b)
								scroll(term, term->curs.y, term->marg_b,
								-def(term->esc_args[0], 1), FALSE);
							seen_disp_event(term);
							break;
						case 'M':       /* DL: delete lines */
							compatibility(VT102);
							CLAMP(term->esc_args[0], term->rows);
							if (term->curs.y <= term->marg_b)
								scroll(term, term->curs.y, term->marg_b,
								def(term->esc_args[0], 1),
								TRUE);
							seen_disp_event(term);
							break;
						case '@':       /* ICH: insert chars */
							/* XXX VTTEST says this is vt220, vt510 manual says vt102 */
							compatibility(VT102);
							CLAMP(term->esc_args[0], term->cols);
							insch(term, def(term->esc_args[0], 1));
							seen_disp_event(term);
							break;
						case 'P':       /* DCH: delete chars */
							compatibility(VT102);
							CLAMP(term->esc_args[0], term->cols);
							insch(term, -def(term->esc_args[0], 1));
							seen_disp_event(term);
							break;
						case 'c':       /* DA: terminal type query */
							compatibility(VT100);
							/* This is the response for a VT102 */
							if (term->ldisc)
								ldisc_send(term->ldisc, term->id_string,
								strlen(term->id_string), 0);
							break;
						case 'n':       /* DSR: cursor position query */
							if (term->ldisc) {
								if (term->esc_args[0] == 6) {
									char buf[32];
									sprintf(buf, "\033[%d;%dR", term->curs.y + 1,
										term->curs.x + 1);
									ldisc_send(term->ldisc, buf, strlen(buf), 0);
								} else if (term->esc_args[0] == 5) {
									ldisc_send(term->ldisc, "\033[0n", 4, 0);
								}
							}
							break;
						case 'h':       /* SM: toggle modes to high */
						case ANSI_QUE('h'):
							compatibility(VT100);
							{
								int i;
								for (i = 0; i < term->esc_nargs; i++)
									toggle_mode(term, term->esc_args[i],
									term->esc_query, TRUE);
							}
							break;
						case 'i':		/* MC: Media copy */
						case ANSI_QUE('i'):
							compatibility(VT100);
							{
								char *printer;
								if (term->esc_nargs != 1) break;
								if (term->esc_args[0] == 5 && 
									(printer = conf_get_str(term->conf,
									CONF_printer))[0]) {
										term->printing = TRUE;
										term->only_printing = !term->esc_query;
										term->print_state = 0;
										term_print_setup(term, printer);
								} else if (term->esc_args[0] == 4 &&
									term->printing) {
										term_print_finish(term);
								}
							}
							break;			
						case 'l':       /* RM: toggle modes to low */
						case ANSI_QUE('l'):
							compatibility(VT100);
							{
								int i;
								for (i = 0; i < term->esc_nargs; i++)
									toggle_mode(term, term->esc_args[i],
									term->esc_query, FALSE);
							}
							break;
						case 'g':       /* TBC: clear tabs */
							compatibility(VT100);
							if (term->esc_nargs == 1) {
								if (term->esc_args[0] == 0) {
									term->tabs[term->curs.x] = FALSE;
								} else if (term->esc_args[0] == 3) {
									int i;
									for (i = 0; i < term->cols; i++)
										term->tabs[i] = FALSE;
								}
							}
							break;
						case 'r':       /* DECSTBM: set scroll margins */
							compatibility(VT100);
							if (term->esc_nargs <= 2) {
								int top, bot;
								CLAMP(term->esc_args[0], term->rows);
								CLAMP(term->esc_args[1], term->rows);
								top = def(term->esc_args[0], 1) - 1;
								bot = (term->esc_nargs <= 1
									|| term->esc_args[1] == 0 ?
									term->rows :
								def(term->esc_args[1], term->rows)) - 1;
								if (bot >= term->rows)
									bot = term->rows - 1;
								/* VTTEST Bug 9 - if region is less than 2 lines
								* don't change region.
								*/
								if (bot - top > 0) {
									term->marg_t = top;
									term->marg_b = bot;
									term->curs.x = 0;
									/*
									* I used to think the cursor should be
									* placed at the top of the newly marginned
									* area. Apparently not: VMS TPU falls over
									* if so.
									*
									* Well actually it should for
									* Origin mode - RDB
									*/
									term->curs.y = (term->dec_om ?
										term->marg_t : 0);
									seen_disp_event(term);
								}
							}
							break;
						case 'm':       /* SGR: set graphics rendition */
							{
								/* 
								* A VT100 without the AVO only had one
								* attribute, either underline or
								* reverse video depending on the
								* cursor type, this was selected by
								* CSI 7m.
								*
								* case 2:
								*  This is sometimes DIM, eg on the
								*  GIGI and Linux
								* case 8:
								*  This is sometimes INVIS various ANSI.
								* case 21:
								*  This like 22 disables BOLD, DIM and INVIS
								*
								* The ANSI colours appear on any
								* terminal that has colour (obviously)
								* but the interaction between sgr0 and
								* the colours varies but is usually
								* related to the background colour
								* erase item. The interaction between
								* colour attributes and the mono ones
								* is also very implementation
								* dependent.
								*
								* The 39 and 49 attributes are likely
								* to be unimplemented.
								*/
								int i;
								for (i = 0; i < term->esc_nargs; i++) {
									switch (def(term->esc_args[i], 0)) {
									case 0:	/* restore defaults */
										term->curr_attr = term->default_attr;
										break;
									case 1:	/* enable bold */
										compatibility(VT100AVO);
										term->curr_attr |= ATTR_BOLD;
										break;
									case 21:	/* (enable double underline) */
										compatibility(OTHER);
									case 4:	/* enable underline */
										compatibility(VT100AVO);
										term->curr_attr |= ATTR_UNDER;
										break;
									case 5:	/* enable blink */
										compatibility(VT100AVO);
										term->curr_attr |= ATTR_BLINK;
										break;
									case 6:	/* SCO light bkgrd */
										compatibility(SCOANSI);
										term->blink_is_real = FALSE;
										term->curr_attr |= ATTR_BLINK;
										term_schedule_tblink(term);
										break;
									case 7:	/* enable reverse video */
										term->curr_attr |= ATTR_REVERSE;
										break;
									case 10:      /* SCO acs off */
										compatibility(SCOANSI);
										if (term->no_remote_charset) break;
										term->sco_acs = 0; break;
									case 11:      /* SCO acs on */
										compatibility(SCOANSI);
										if (term->no_remote_charset) break;
										term->sco_acs = 1; break;
									case 12:      /* SCO acs on, |0x80 */
										compatibility(SCOANSI);
										if (term->no_remote_charset) break;
										term->sco_acs = 2; break;
									case 22:	/* disable bold */
										compatibility2(OTHER, VT220);
										term->curr_attr &= ~ATTR_BOLD;
										break;
									case 24:	/* disable underline */
										compatibility2(OTHER, VT220);
										term->curr_attr &= ~ATTR_UNDER;
										break;
									case 25:	/* disable blink */
										compatibility2(OTHER, VT220);
										term->curr_attr &= ~ATTR_BLINK;
										break;
									case 27:	/* disable reverse video */
										compatibility2(OTHER, VT220);
										term->curr_attr &= ~ATTR_REVERSE;
										break;
									case 30:
									case 31:
									case 32:
									case 33:
									case 34:
									case 35:
									case 36:
									case 37:
										/* foreground */
										term->curr_attr &= ~ATTR_FGMASK;
										term->curr_attr |=
											(term->esc_args[i] - 30)<<ATTR_FGSHIFT;
										break;
									case 90:
									case 91:
									case 92:
									case 93:
									case 94:
									case 95:
									case 96:
									case 97:
										/* aixterm-style bright foreground */
										term->curr_attr &= ~ATTR_FGMASK;
										term->curr_attr |=
											((term->esc_args[i] - 90 + 8)
											<< ATTR_FGSHIFT);
										break;
									case 39:	/* default-foreground */
										term->curr_attr &= ~ATTR_FGMASK;
										term->curr_attr |= ATTR_DEFFG;
										break;
									case 40:
									case 41:
									case 42:
									case 43:
									case 44:
									case 45:
									case 46:
									case 47:
										/* background */
										term->curr_attr &= ~ATTR_BGMASK;
										term->curr_attr |=
											(term->esc_args[i] - 40)<<ATTR_BGSHIFT;
										break;
									case 100:
									case 101:
									case 102:
									case 103:
									case 104:
									case 105:
									case 106:
									case 107:
										/* aixterm-style bright background */
										term->curr_attr &= ~ATTR_BGMASK;
										term->curr_attr |=
											((term->esc_args[i] - 100 + 8)
											<< ATTR_BGSHIFT);
										break;
									case 49:	/* default-background */
										term->curr_attr &= ~ATTR_BGMASK;
										term->curr_attr |= ATTR_DEFBG;
										break;
									case 38:   /* xterm 256-colour mode */
										if (i+2 < term->esc_nargs &&
											term->esc_args[i+1] == 5) {
												term->curr_attr &= ~ATTR_FGMASK;
												term->curr_attr |=
													((term->esc_args[i+2] & 0xFF)
													<< ATTR_FGSHIFT);
												i += 2;
										}
										break;
									case 48:   /* xterm 256-colour mode */
										if (i+2 < term->esc_nargs &&
											term->esc_args[i+1] == 5) {
												term->curr_attr &= ~ATTR_BGMASK;
												term->curr_attr |=
													((term->esc_args[i+2] & 0xFF)
													<< ATTR_BGSHIFT);
												i += 2;
										}
										break;
									}
								}
								set_erase_char(term);
							}
							break;
						case 's':       /* save cursor */
							save_cursor(term, TRUE);
							break;
						case 'u':       /* restore cursor */
							save_cursor(term, FALSE);
							seen_disp_event(term);
							break;
						case 't': /* DECSLPP: set page size - ie window height */
							/*
							* VT340/VT420 sequence DECSLPP, DEC only allows values
							*  24/25/36/48/72/144 other emulators (eg dtterm) use
							* illegal values (eg first arg 1..9) for window changing 
							* and reports.
							*/
							if (term->esc_nargs <= 1
								&& (term->esc_args[0] < 1 ||
								term->esc_args[0] >= 24)) {
									compatibility(VT340TEXT);
									if (!term->no_remote_resize)
										request_resize(term->frontend, term->cols,
										def(term->esc_args[0], 24));
									deselect(term);
							} else if (term->esc_nargs >= 1 &&
								term->esc_args[0] >= 1 &&
								term->esc_args[0] < 24) {
									compatibility(OTHER);

									switch (term->esc_args[0]) {
										int x, y, len;
										char buf[80];
										const char *p;
									case 1:
										set_iconic(term->frontend, FALSE);
										break;
									case 2:
										set_iconic(term->frontend, TRUE);
										break;
									case 3:
										if (term->esc_nargs >= 3) {
											if (!term->no_remote_resize)
												move_window(term->frontend,
												def(term->esc_args[1], 0),
												def(term->esc_args[2], 0));
										}
										break;
									case 4:
										/* We should resize the window to a given
										* size in pixels here, but currently our
										* resizing code isn't healthy enough to
										* manage it. */
										break;
									case 5:
										/* move to top */
										set_zorder(term->frontend, TRUE);
										break;
									case 6:
										/* move to bottom */
										set_zorder(term->frontend, FALSE);
										break;
									case 7:
										refresh_window(term->frontend);
										break;
									case 8:
										if (term->esc_nargs >= 3) {
											if (!term->no_remote_resize)
												request_resize(term->frontend,
												def(term->esc_args[2], term->conf_width),
												def(term->esc_args[1], term->conf_height));
										}
										break;
									case 9:
										if (term->esc_nargs >= 2)
											set_zoomed(term->frontend,
											term->esc_args[1] ?
TRUE : FALSE);
										break;
									case 11:
										if (term->ldisc)
											ldisc_send(term->ldisc,
											is_iconic(term->frontend) ?
											"\033[2t" : "\033[1t", 4, 0);
										break;
									case 13:
										if (term->ldisc) {
											get_window_pos(term->frontend, &x, &y);
											len = sprintf(buf, "\033[3;%u;%ut",
												(unsigned)x,
												(unsigned)y);
											ldisc_send(term->ldisc, buf, len, 0);
										}
										break;
									case 14:
										if (term->ldisc) {
											get_window_pixels(term->frontend, &x, &y);
											len = sprintf(buf, "\033[4;%d;%dt", y, x);
											ldisc_send(term->ldisc, buf, len, 0);
										}
										break;
									case 18:
										if (term->ldisc) {
											len = sprintf(buf, "\033[8;%d;%dt",
												term->rows, term->cols);
											ldisc_send(term->ldisc, buf, len, 0);
										}
										break;
									case 19:
										/*
										* Hmmm. Strictly speaking we
										* should return `the size of the
										* screen in characters', but
										* that's not easy: (a) window
										* furniture being what it is it's
										* hard to compute, and (b) in
										* resize-font mode maximising the
										* window wouldn't change the
										* number of characters. *shrug*. I
										* think we'll ignore it for the
										* moment and see if anyone
										* complains, and then ask them
										* what they would like it to do.
										*/
										break;
									case 20:
										if (term->ldisc &&
											term->remote_qtitle_action != TITLE_NONE) {
												if(term->remote_qtitle_action == TITLE_REAL)
													p = get_window_title(term->frontend, TRUE);
												else
													p = EMPTY_WINDOW_TITLE;
												len = strlen(p);
												ldisc_send(term->ldisc, "\033]L", 3, 0);
												ldisc_send(term->ldisc, p, len, 0);
												ldisc_send(term->ldisc, "\033\\", 2, 0);
										}
										break;
									case 21:
										if (term->ldisc &&
											term->remote_qtitle_action != TITLE_NONE) {
												if(term->remote_qtitle_action == TITLE_REAL)
													p = get_window_title(term->frontend, FALSE);
												else
													p = EMPTY_WINDOW_TITLE;
												len = strlen(p);
												ldisc_send(term->ldisc, "\033]l", 3, 0);
												ldisc_send(term->ldisc, p, len, 0);
												ldisc_send(term->ldisc, "\033\\", 2, 0);
										}
										break;
									}
							}
							break;
						case 'S':		/* SU: Scroll up */
							CLAMP(term->esc_args[0], term->rows);
							compatibility(SCOANSI);
							scroll(term, term->marg_t, term->marg_b,
								def(term->esc_args[0], 1), TRUE);
							term->wrapnext = FALSE;
							seen_disp_event(term);
							break;
						case 'T':		/* SD: Scroll down */
							CLAMP(term->esc_args[0], term->rows);
							compatibility(SCOANSI);
							scroll(term, term->marg_t, term->marg_b,
								-def(term->esc_args[0], 1), TRUE);
							term->wrapnext = FALSE;
							seen_disp_event(term);
							break;
						case ANSI('|', '*'): /* DECSNLS */
							/* 
							* Set number of lines on screen
							* VT420 uses VGA like hardware and can
							* support any size in reasonable range
							* (24..49 AIUI) with no default specified.
							*/
							compatibility(VT420);
							if (term->esc_nargs == 1 && term->esc_args[0] > 0) {
								if (!term->no_remote_resize)
									request_resize(term->frontend, term->cols,
									def(term->esc_args[0],
									term->conf_height));
								deselect(term);
							}
							break;
						case ANSI('|', '$'): /* DECSCPP */
							/*
							* Set number of columns per page
							* Docs imply range is only 80 or 132, but
							* I'll allow any.
							*/
							compatibility(VT340TEXT);
							if (term->esc_nargs <= 1) {
								if (!term->no_remote_resize)
									request_resize(term->frontend,
									def(term->esc_args[0],
									term->conf_width),
									term->rows);
								deselect(term);
							}
							break;
						case 'X':     /* ECH: write N spaces w/o moving cursor */
							/* XXX VTTEST says this is vt220, vt510 manual
							* says vt100 */
							compatibility(ANSIMIN);
							CLAMP(term->esc_args[0], term->cols);
							{
								int n = def(term->esc_args[0], 1);
								pos cursplus;
								int p = term->curs.x;
								termline *cline = scrlineptr(term->curs.y);

								if (n > term->cols - term->curs.x)
									n = term->cols - term->curs.x;
								cursplus = term->curs;
								cursplus.x += n;
								check_boundary(term, term->curs.x, term->curs.y);
								check_boundary(term, term->curs.x+n, term->curs.y);
								check_selection(term, term->curs, cursplus);
								while (n--)
									copy_termchar(cline, p++,
									&term->erase_char);
								seen_disp_event(term);
							}
							break;
						case 'x':       /* DECREQTPARM: report terminal characteristics */
							compatibility(VT100);
							if (term->ldisc) {
								char buf[32];
								int i = def(term->esc_args[0], 0);
								if (i == 0 || i == 1) {
									strcpy(buf, "\033[2;1;1;112;112;1;0x");
									buf[2] += i;
									ldisc_send(term->ldisc, buf, 20, 0);
								}
							}
							break;
						case 'Z':		/* CBT */
							compatibility(OTHER);
							CLAMP(term->esc_args[0], term->cols);
							{
								int i = def(term->esc_args[0], 1);
								pos old_curs = term->curs;

								for(;i>0 && term->curs.x>0; i--) {
									do {
										term->curs.x--;
									} while (term->curs.x >0 &&
										!term->tabs[term->curs.x]);
								}
								check_selection(term, old_curs, term->curs);
							}
							break;
						case ANSI('c', '='):      /* Hide or Show Cursor */
							compatibility(SCOANSI);
							switch(term->esc_args[0]) {
							case 0:  /* hide cursor */
								term->cursor_on = FALSE;
								break;
							case 1:  /* restore cursor */
								term->big_cursor = FALSE;
								term->cursor_on = TRUE;
								break;
							case 2:  /* block cursor */
								term->big_cursor = TRUE;
								term->cursor_on = TRUE;
								break;
							}
							break;
						case ANSI('C', '='):
							/*
							* set cursor start on scanline esc_args[0] and
							* end on scanline esc_args[1].If you set
							* the bottom scan line to a value less than
							* the top scan line, the cursor will disappear.
							*/
							compatibility(SCOANSI);
							if (term->esc_nargs >= 2) {
								if (term->esc_args[0] > term->esc_args[1])
									term->cursor_on = FALSE;
								else
									term->cursor_on = TRUE;
							}
							break;
						case ANSI('D', '='):
							compatibility(SCOANSI);
							term->blink_is_real = FALSE;
							term_schedule_tblink(term);
							if (term->esc_args[0]>=1)
								term->curr_attr |= ATTR_BLINK;
							else
								term->curr_attr &= ~ATTR_BLINK;
							break;
						case ANSI('E', '='):
							compatibility(SCOANSI);
							term->blink_is_real = (term->esc_args[0] >= 1);
							term_schedule_tblink(term);
							break;
						case ANSI('F', '='):      /* set normal foreground */
							compatibility(SCOANSI);
							if (term->esc_args[0] < 16) {
								long colour =
									(sco2ansicolour[term->esc_args[0] & 0x7] |
									(term->esc_args[0] & 0x8)) <<
									ATTR_FGSHIFT;
								term->curr_attr &= ~ATTR_FGMASK;
								term->curr_attr |= colour;
								term->default_attr &= ~ATTR_FGMASK;
								term->default_attr |= colour;
								set_erase_char(term);
							}
							break;
						case ANSI('G', '='):      /* set normal background */
							compatibility(SCOANSI);
							if (term->esc_args[0] < 16) {
								long colour =
									(sco2ansicolour[term->esc_args[0] & 0x7] |
									(term->esc_args[0] & 0x8)) <<
									ATTR_BGSHIFT;
								term->curr_attr &= ~ATTR_BGMASK;
								term->curr_attr |= colour;
								term->default_attr &= ~ATTR_BGMASK;
								term->default_attr |= colour;
								set_erase_char(term);
							}
							break;
						case ANSI('L', '='):
							compatibility(SCOANSI);
							term->use_bce = (term->esc_args[0] <= 0);
							set_erase_char(term);
							break;
						case ANSI('p', '"'): /* DECSCL: set compat level */
							/*
							* Allow the host to make this emulator a
							* 'perfect' VT102. This first appeared in
							* the VT220, but we do need to get back to
							* PuTTY mode so I won't check it.
							*
							* The arg in 40..42,50 are a PuTTY extension.
							* The 2nd arg, 8bit vs 7bit is not checked.
							*
							* Setting VT102 mode should also change
							* the Fkeys to generate PF* codes as a
							* real VT102 has no Fkeys. The VT220 does
							* this, F11..F13 become ESC,BS,LF other
							* Fkeys send nothing.
							*
							* Note ESC c will NOT change this!
							*/

							switch (term->esc_args[0]) {
							case 61:
								term->compatibility_level &= ~TM_VTXXX;
								term->compatibility_level |= TM_VT102;
								break;
							case 62:
								term->compatibility_level &= ~TM_VTXXX;
								term->compatibility_level |= TM_VT220;
								break;

							default:
								if (term->esc_args[0] > 60 &&
									term->esc_args[0] < 70)
									term->compatibility_level |= TM_VTXXX;
								break;

							case 40:
								term->compatibility_level &= TM_VTXXX;
								break;
							case 41:
								term->compatibility_level = TM_PUTTY;
								break;
							case 42:
								term->compatibility_level = TM_SCOANSI;
								break;

							case ARG_DEFAULT:
								term->compatibility_level = TM_PUTTY;
								break;
							case 50:
								break;
							}

							/* Change the response to CSI c */
							if (term->esc_args[0] == 50) {
								int i;
								char lbuf[64];
								strcpy(term->id_string, "\033[?");
								for (i = 1; i < term->esc_nargs; i++) {
									if (i != 1)
										strcat(term->id_string, ";");
									sprintf(lbuf, "%u", term->esc_args[i]);
									strcat(term->id_string, lbuf);
								}
								strcat(term->id_string, "c");
							}
#if 0
							/* Is this a good idea ? 
							* Well we should do a soft reset at this point ...
							*/
							if (!has_compat(VT420) && has_compat(VT100)) {
								if (!term->no_remote_resize) {
									if (term->reset_132)
										request_resize(132, 24);
									else
										request_resize(80, 24);
								}
							}
#endif
							break;
					}
					break;
				case SEEN_OSC:
					term->osc_w = FALSE;
					switch (c) {
					case 'P':	       /* Linux palette sequence */
						term->termstate = SEEN_OSC_P;
						term->osc_strlen = 0;
						break;
					case 'R':	       /* Linux palette reset */
						palette_reset(term->frontend);
						term_invalidate(term);
						term->termstate = TOPLEVEL;
						break;
					case 'W':	       /* word-set */
						term->termstate = SEEN_OSC_W;
						term->osc_w = TRUE;
						break;
					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
					case '5':
					case '6':
					case '7':
					case '8':
					case '9':
						if (term->esc_args[0] <= UINT_MAX / 10 &&
							term->esc_args[0] * 10 <= UINT_MAX - c - '0')
							term->esc_args[0] = 10 * term->esc_args[0] + c - '0';
						else
							term->esc_args[0] = UINT_MAX;
						break;
					case 'L':
						/*
						* Grotty hack to support xterm and DECterm title
						* sequences concurrently.
						*/
						if (term->esc_args[0] == 2) {
							term->esc_args[0] = 1;
							break;
						}
						/* else fall through */
					default:
						term->termstate = OSC_STRING;
						term->osc_strlen = 0;
					}
					break;
				case OSC_STRING:
					/*
					* This OSC stuff is EVIL. It takes just one character to get into
					* sysline mode and it's not initially obvious how to get out.
					* So I've added CR and LF as string aborts.
					* This shouldn't effect compatibility as I believe embedded 
					* control characters are supposed to be interpreted (maybe?) 
					* and they don't display anything useful anyway.
					*
					* -- RDB
					*/
					if (c == '\012' || c == '\015') {
						term->termstate = TOPLEVEL;
					} else if (c == 0234 || c == '\007') {
						/*
						* These characters terminate the string; ST and BEL
						* terminate the sequence and trigger instant
						* processing of it, whereas ESC goes back to SEEN_ESC
						* mode unless it is followed by \, in which case it is
						* synonymous with ST in the first place.
						*/
						do_osc(term);
						term->termstate = TOPLEVEL;
					} else if (c == '\033')
						term->termstate = OSC_MAYBE_ST;
					else if (term->osc_strlen < OSC_STR_MAX)
						term->osc_string[term->osc_strlen++] = (char)c;
					break;
				case SEEN_OSC_P:
					{
						int max = (term->osc_strlen == 0 ? 21 : 15);
						int val;
						if ((int)c >= '0' && (int)c <= '9')
							val = c - '0';
						else if ((int)c >= 'A' && (int)c <= 'A' + max - 10)
							val = c - 'A' + 10;
						else if ((int)c >= 'a' && (int)c <= 'a' + max - 10)
							val = c - 'a' + 10;
						else {
							term->termstate = TOPLEVEL;
							break;
						}
						term->osc_string[term->osc_strlen++] = val;
						if (term->osc_strlen >= 7) {
							palette_set(term->frontend, term->osc_string[0],
								term->osc_string[1] * 16 + term->osc_string[2],
								term->osc_string[3] * 16 + term->osc_string[4],
								term->osc_string[5] * 16 + term->osc_string[6]);
							term_invalidate(term);
							term->termstate = TOPLEVEL;
						}
					}
					break;
				case SEEN_OSC_W:
					switch (c) {
					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
					case '5':
					case '6':
					case '7':
					case '8':
					case '9':
						if (term->esc_args[0] <= UINT_MAX / 10 &&
							term->esc_args[0] * 10 <= UINT_MAX - c - '0')
							term->esc_args[0] = 10 * term->esc_args[0] + c - '0';
						else
							term->esc_args[0] = UINT_MAX;
						break;
					default:
						term->termstate = OSC_STRING;
						term->osc_strlen = 0;
					}
					break;
				case VT52_ESC:
					term->termstate = TOPLEVEL;
					seen_disp_event(term);
					switch (c) {
					case 'A':
						move(term, term->curs.x, term->curs.y - 1, 1);
						break;
					case 'B':
						move(term, term->curs.x, term->curs.y + 1, 1);
						break;
					case 'C':
						move(term, term->curs.x + 1, term->curs.y, 1);
						break;
					case 'D':
						move(term, term->curs.x - 1, term->curs.y, 1);
						break;
						/*
						* From the VT100 Manual
						* NOTE: The special graphics characters in the VT100
						*       are different from those in the VT52
						*
						* From VT102 manual:
						*       137 _  Blank             - Same
						*       140 `  Reserved          - Humm.
						*       141 a  Solid rectangle   - Similar
						*       142 b  1/                - Top half of fraction for the
						*       143 c  3/                - subscript numbers below.
						*       144 d  5/
						*       145 e  7/
						*       146 f  Degrees           - Same
						*       147 g  Plus or minus     - Same
						*       150 h  Right arrow
						*       151 i  Ellipsis (dots)
						*       152 j  Divide by
						*       153 k  Down arrow
						*       154 l  Bar at scan 0
						*       155 m  Bar at scan 1
						*       156 n  Bar at scan 2
						*       157 o  Bar at scan 3     - Similar
						*       160 p  Bar at scan 4     - Similar
						*       161 q  Bar at scan 5     - Similar
						*       162 r  Bar at scan 6     - Same
						*       163 s  Bar at scan 7     - Similar
						*       164 t  Subscript 0
						*       165 u  Subscript 1
						*       166 v  Subscript 2
						*       167 w  Subscript 3
						*       170 x  Subscript 4
						*       171 y  Subscript 5
						*       172 z  Subscript 6
						*       173 {  Subscript 7
						*       174 |  Subscript 8
						*       175 }  Subscript 9
						*       176 ~  Paragraph
						*
						*/
					case 'F':
						term->cset_attr[term->cset = 0] = CSET_LINEDRW;
						break;
					case 'G':
						term->cset_attr[term->cset = 0] = CSET_ASCII;
						break;
					case 'H':
						move(term, 0, 0, 0);
						break;
					case 'I':
						if (term->curs.y == 0)
							scroll(term, 0, term->rows - 1, -1, TRUE);
						else if (term->curs.y > 0)
							term->curs.y--;
						term->wrapnext = FALSE;
						break;
					case 'J':
						erase_lots(term, FALSE, FALSE, TRUE);
						if (term->scroll_on_disp)
							term->disptop = 0;
						break;
					case 'K':
						erase_lots(term, TRUE, FALSE, TRUE);
						break;
#if 0
					case 'V':
						/* XXX Print cursor line */
						break;
					case 'W':
						/* XXX Start controller mode */
						break;
					case 'X':
						/* XXX Stop controller mode */
						break;
#endif
					case 'Y':
						term->termstate = VT52_Y1;
						break;
					case 'Z':
						if (term->ldisc)
							ldisc_send(term->ldisc, "\033/Z", 3, 0);
						break;
					case '=':
						term->app_keypad_keys = TRUE;
						break;
					case '>':
						term->app_keypad_keys = FALSE;
						break;
					case '<':
						/* XXX This should switch to VT100 mode not current or default
						*     VT mode. But this will only have effect in a VT220+
						*     emulation.
						*/
						term->vt52_mode = FALSE;
						term->blink_is_real = term->blinktext;
						term_schedule_tblink(term);
						break;
#if 0
					case '^':
						/* XXX Enter auto print mode */
						break;
					case '_':
						/* XXX Exit auto print mode */
						break;
					case ']':
						/* XXX Print screen */
						break;
#endif

#ifdef VT52_PLUS
					case 'E':
						/* compatibility(ATARI) */
						move(term, 0, 0, 0);
						erase_lots(term, FALSE, FALSE, TRUE);
						if (term->scroll_on_disp)
							term->disptop = 0;
						break;
					case 'L':
						/* compatibility(ATARI) */
						if (term->curs.y <= term->marg_b)
							scroll(term, term->curs.y, term->marg_b, -1, FALSE);
						break;
					case 'M':
						/* compatibility(ATARI) */
						if (term->curs.y <= term->marg_b)
							scroll(term, term->curs.y, term->marg_b, 1, TRUE);
						break;
					case 'b':
						/* compatibility(ATARI) */
						term->termstate = VT52_FG;
						break;
					case 'c':
						/* compatibility(ATARI) */
						term->termstate = VT52_BG;
						break;
					case 'd':
						/* compatibility(ATARI) */
						erase_lots(term, FALSE, TRUE, FALSE);
						if (term->scroll_on_disp)
							term->disptop = 0;
						break;
					case 'e':
						/* compatibility(ATARI) */
						term->cursor_on = TRUE;
						break;
					case 'f':
						/* compatibility(ATARI) */
						term->cursor_on = FALSE;
						break;
						/* case 'j': Save cursor position - broken on ST */
						/* case 'k': Restore cursor position */
					case 'l':
						/* compatibility(ATARI) */
						erase_lots(term, TRUE, TRUE, TRUE);
						term->curs.x = 0;
						term->wrapnext = FALSE;
						break;
					case 'o':
						/* compatibility(ATARI) */
						erase_lots(term, TRUE, TRUE, FALSE);
						break;
					case 'p':
						/* compatibility(ATARI) */
						term->curr_attr |= ATTR_REVERSE;
						break;
					case 'q':
						/* compatibility(ATARI) */
						term->curr_attr &= ~ATTR_REVERSE;
						break;
					case 'v':	       /* wrap Autowrap on - Wyse style */
						/* compatibility(ATARI) */
						term->wrap = 1;
						break;
					case 'w':	       /* Autowrap off */
						/* compatibility(ATARI) */
						term->wrap = 0;
						break;

					case 'R':
						/* compatibility(OTHER) */
						term->vt52_bold = FALSE;
						term->curr_attr = ATTR_DEFAULT;
						set_erase_char(term);
						break;
					case 'S':
						/* compatibility(VI50) */
						term->curr_attr |= ATTR_UNDER;
						break;
					case 'W':
						/* compatibility(VI50) */
						term->curr_attr &= ~ATTR_UNDER;
						break;
					case 'U':
						/* compatibility(VI50) */
						term->vt52_bold = TRUE;
						term->curr_attr |= ATTR_BOLD;
						break;
					case 'T':
						/* compatibility(VI50) */
						term->vt52_bold = FALSE;
						term->curr_attr &= ~ATTR_BOLD;
						break;
#endif
					}
					break;
				case VT52_Y1:
					term->termstate = VT52_Y2;
					move(term, term->curs.x, c - ' ', 0);
					break;
				case VT52_Y2:
					term->termstate = TOPLEVEL;
					move(term, c - ' ', term->curs.y, 0);
					break;

#ifdef VT52_PLUS
				case VT52_FG:
					term->termstate = TOPLEVEL;
					term->curr_attr &= ~ATTR_FGMASK;
					term->curr_attr &= ~ATTR_BOLD;
					term->curr_attr |= (c & 0xF) << ATTR_FGSHIFT;
					set_erase_char(term);
					break;
				case VT52_BG:
					term->termstate = TOPLEVEL;
					term->curr_attr &= ~ATTR_BGMASK;
					term->curr_attr &= ~ATTR_BLINK;
					term->curr_attr |= (c & 0xF) << ATTR_BGSHIFT;
					set_erase_char(term);
					break;
#endif
				default: break;	       /* placate gcc warning about enum use */
			}
			if (term->selstate != NO_SELECTION) {
				pos cursplus = term->curs;
				incpos(cursplus);
				check_selection(term, term->curs, cursplus);
			}
	}

	term_print_flush(term);
	if (term->logflush && term->logctx)
		logflush(term->logctx);
}

/*
* To prevent having to run the reasonably tricky bidi algorithm
* too many times, we maintain a cache of the last lineful of data
* fed to the algorithm on each line of the display.
*/
static int term_bidi_cache_hit(Terminal *term, int line,
	termchar *lbefore, int width)
{
	int i;

	if (!term->pre_bidi_cache)
		return FALSE;		       /* cache doesn't even exist yet! */

	if (line >= term->bidi_cache_size)
		return FALSE;		       /* cache doesn't have this many lines */

	if (!term->pre_bidi_cache[line].chars)
		return FALSE;		       /* cache doesn't contain _this_ line */

	if (term->pre_bidi_cache[line].width != width)
		return FALSE;		       /* line is wrong width */

	for (i = 0; i < width; i++)
		if (!termchars_equal(term->pre_bidi_cache[line].chars+i, lbefore+i))
			return FALSE;	       /* line doesn't match cache */

	return TRUE;		       /* it didn't match. */
}

static void term_bidi_cache_store(Terminal *term, int line, termchar *lbefore,
	termchar *lafter, bidi_char *wcTo,
	int width, int size)
{
	int i;

	if (!term->pre_bidi_cache || term->bidi_cache_size <= line) {
		int j = term->bidi_cache_size;
		term->bidi_cache_size = line+1;
		term->pre_bidi_cache = sresize(term->pre_bidi_cache,
			term->bidi_cache_size,
		struct bidi_cache_entry);
		term->post_bidi_cache = sresize(term->post_bidi_cache,
			term->bidi_cache_size,
		struct bidi_cache_entry);
		while (j < term->bidi_cache_size) {
			term->pre_bidi_cache[j].chars =
				term->post_bidi_cache[j].chars = NULL;
			term->pre_bidi_cache[j].width =
				term->post_bidi_cache[j].width = -1;
			term->pre_bidi_cache[j].forward =
				term->post_bidi_cache[j].forward = NULL;
			term->pre_bidi_cache[j].backward =
				term->post_bidi_cache[j].backward = NULL;
			j++;
		}
	}

	sfree(term->pre_bidi_cache[line].chars);
	sfree(term->post_bidi_cache[line].chars);
	sfree(term->post_bidi_cache[line].forward);
	sfree(term->post_bidi_cache[line].backward);

	term->pre_bidi_cache[line].width = width;
	term->pre_bidi_cache[line].chars = snewn(size, termchar);
	term->post_bidi_cache[line].width = width;
	term->post_bidi_cache[line].chars = snewn(size, termchar);
	term->post_bidi_cache[line].forward = snewn(width, int);
	term->post_bidi_cache[line].backward = snewn(width, int);

	memcpy(term->pre_bidi_cache[line].chars, lbefore, size * TSIZE);
	memcpy(term->post_bidi_cache[line].chars, lafter, size * TSIZE);
	memset(term->post_bidi_cache[line].forward, 0, width * sizeof(int));
	memset(term->post_bidi_cache[line].backward, 0, width * sizeof(int));

	for (i = 0; i < width; i++) {
		int p = wcTo[i].index;

		assert(0 <= p && p < width);

		term->post_bidi_cache[line].backward[i] = p;
		term->post_bidi_cache[line].forward[p] = i;
	}
}

/*
* Prepare the bidi information for a screen line. Returns the
* transformed list of termchars, or NULL if no transformation at
* all took place (because bidi is disabled). If return was
* non-NULL, auxiliary information such as the forward and reverse
* mappings of permutation position are available in
* term->post_bidi_cache[scr_y].*.
*/
static termchar *term_bidi_line(Terminal *term, struct termline *ldata,
	int scr_y)
{
	termchar *lchars;
	int it;

	/* Do Arabic shaping and bidi. */
	if(!term->bidi || !term->arabicshaping) {

		if (!term_bidi_cache_hit(term, scr_y, ldata->chars, term->cols)) {

			if (term->wcFromTo_size < term->cols) {
				term->wcFromTo_size = term->cols;
				term->wcFrom = sresize(term->wcFrom, term->wcFromTo_size,
					bidi_char);
				term->wcTo = sresize(term->wcTo, term->wcFromTo_size,
					bidi_char);
			}

			for(it=0; it<term->cols ; it++)
			{
				unsigned long uc = (ldata->chars[it].chr);

				switch (uc & CSET_MASK) {
				case CSET_LINEDRW:
					if (!term->rawcnp) {
						uc = term->ucsdata->unitab_xterm[uc & 0xFF];
						break;
					}
				case CSET_ASCII:
					uc = term->ucsdata->unitab_line[uc & 0xFF];
					break;
				case CSET_SCOACS:
					uc = term->ucsdata->unitab_scoacs[uc&0xFF];
					break;
				}
				switch (uc & CSET_MASK) {
				case CSET_ACP:
					uc = term->ucsdata->unitab_font[uc & 0xFF];
					break;
				case CSET_OEMCP:
					uc = term->ucsdata->unitab_oemcp[uc & 0xFF];
					break;
				}

				term->wcFrom[it].origwc = term->wcFrom[it].wc =
					(unsigned int)uc;
				term->wcFrom[it].index = it;
			}

			if(!term->bidi)
				do_bidi(term->wcFrom, term->cols);

			/* this is saved iff done from inside the shaping */
			if(!term->bidi && term->arabicshaping)
				for(it=0; it<term->cols; it++)
					term->wcTo[it] = term->wcFrom[it];

			if(!term->arabicshaping)
				do_shape(term->wcFrom, term->wcTo, term->cols);

			if (term->ltemp_size < ldata->size) {
				term->ltemp_size = ldata->size;
				term->ltemp = sresize(term->ltemp, term->ltemp_size,
					termchar);
			}

			memcpy(term->ltemp, ldata->chars, ldata->size * TSIZE);

			for(it=0; it<term->cols ; it++)
			{
				term->ltemp[it] = ldata->chars[term->wcTo[it].index];
				if (term->ltemp[it].cc_next)
					term->ltemp[it].cc_next -=
					it - term->wcTo[it].index;

				if (term->wcTo[it].origwc != term->wcTo[it].wc)
					term->ltemp[it].chr = term->wcTo[it].wc;
			}
			term_bidi_cache_store(term, scr_y, ldata->chars,
				term->ltemp, term->wcTo,
				term->cols, ldata->size);

			lchars = term->ltemp;
		} else {
			lchars = term->post_bidi_cache[scr_y].chars;
		}
	} else {
		lchars = NULL;
	}

	return lchars;
}

/*
* Given a context, update the window. Out of paranoia, we don't
* allow WM_PAINT responses to do scrolling optimisations.
*/
static void do_paint(Terminal *term, Context ctx, int may_optimise)
{
	int i, j, our_curs_y, our_curs_x;
	int rv, cursor;
	pos scrpos;
	wchar_t *ch;
	int chlen;
#ifdef OPTIMISE_SCROLL
	struct scrollregion *sr;
#endif /* OPTIMISE_SCROLL */
	termchar *newline;

	chlen = 1024;
	ch = snewn(chlen, wchar_t);

	newline = snewn(term->cols, termchar);

	rv = (!term->rvideo ^ !term->in_vbell ? ATTR_REVERSE : 0);

	/* Depends on:
	* screen array, disptop, scrtop,
	* selection, rv, 
	* blinkpc, blink_is_real, tblinker, 
	* curs.y, curs.x, cblinker, blink_cur, cursor_on, has_focus, wrapnext
	*/

	/* Has the cursor position or type changed ? */
	if (term->cursor_on) {
		if (term->has_focus) {
			if (term->cblinker || !term->blink_cur)
				cursor = TATTR_ACTCURS;
			else
				cursor = 0;
		} else
			cursor = TATTR_PASCURS;
		if (term->wrapnext)
			cursor |= TATTR_RIGHTCURS;
	} else
		cursor = 0;
	our_curs_y = term->curs.y - term->disptop;
	{
		/*
		* Adjust the cursor position:
		*  - for bidi
		*  - in the case where it's resting on the right-hand half
		*    of a CJK wide character. xterm's behaviour here,
		*    which seems adequate to me, is to display the cursor
		*    covering the _whole_ character, exactly as if it were
		*    one space to the left.
		*/
		termline *ldata = lineptr(term->curs.y);
		termchar *lchars;

		our_curs_x = term->curs.x;

		if ( (lchars = term_bidi_line(term, ldata, our_curs_y)) != NULL) {
			our_curs_x = term->post_bidi_cache[our_curs_y].forward[our_curs_x];
		} else
			lchars = ldata->chars;

		if (our_curs_x > 0 &&
			lchars[our_curs_x].chr == UCSWIDE)
			our_curs_x--;

		unlineptr(ldata);
	}

	/*
	* If the cursor is not where it was last time we painted, and
	* its previous position is visible on screen, invalidate its
	* previous position.
	*/
	if (term->dispcursy >= 0 &&
		(term->curstype != cursor ||
		term->dispcursy != our_curs_y ||
		term->dispcursx != our_curs_x)) {
			termchar *dispcurs = term->disptext[term->dispcursy]->chars +
				term->dispcursx;

			if (term->dispcursx > 0 && dispcurs->chr == UCSWIDE)
				dispcurs[-1].attr |= ATTR_INVALID;
			if (term->dispcursx < term->cols-1 && dispcurs[1].chr == UCSWIDE)
				dispcurs[1].attr |= ATTR_INVALID;
			dispcurs->attr |= ATTR_INVALID;

			term->curstype = 0;
	}
	term->dispcursx = term->dispcursy = -1;

#ifdef OPTIMISE_SCROLL
	/* Do scrolls */
	sr = term->scrollhead;
	while (sr) {
		struct scrollregion *next = sr->next;
		do_scroll(ctx, sr->topline, sr->botline, sr->lines);
		sfree(sr);
		sr = next;
	}
	term->scrollhead = term->scrolltail = NULL;
#endif /* OPTIMISE_SCROLL */

	/* The normal screen data */
	for (i = 0; i < term->rows; i++) {
		termline *ldata;
		termchar *lchars;
		int dirty_line, dirty_run, selected;
		unsigned long attr = 0, cset = 0;
		int start = 0;
		int ccount = 0;
		int last_run_dirty = 0;
		int laststart, dirtyrect;
		int *backward;

		scrpos.y = i + term->disptop;
		ldata = lineptr(scrpos.y);

		/* Do Arabic shaping and bidi. */
		lchars = term_bidi_line(term, ldata, i);
		if (lchars) {
			backward = term->post_bidi_cache[i].backward;
		} else {
			lchars = ldata->chars;
			backward = NULL;
		}

		/*
		* First loop: work along the line deciding what we want
		* each character cell to look like.
		*/
		for (j = 0; j < term->cols; j++) {
			unsigned long tattr, tchar;
			termchar *d = lchars + j;
			scrpos.x = backward ? backward[j] : j;

			tchar = d->chr;
			tattr = d->attr;

			if (!term->ansi_colour)
				tattr = (tattr & ~(ATTR_FGMASK | ATTR_BGMASK)) | 
				ATTR_DEFFG | ATTR_DEFBG;

			if (!term->xterm_256_colour) {
				int colour;
				colour = (tattr & ATTR_FGMASK) >> ATTR_FGSHIFT;
				if (colour >= 16 && colour < 256)
					tattr = (tattr &~ ATTR_FGMASK) | ATTR_DEFFG;
				colour = (tattr & ATTR_BGMASK) >> ATTR_BGSHIFT;
				if (colour >= 16 && colour < 256)
					tattr = (tattr &~ ATTR_BGMASK) | ATTR_DEFBG;
			}

			switch (tchar & CSET_MASK) {
			case CSET_ASCII:
				tchar = term->ucsdata->unitab_line[tchar & 0xFF];
				break;
			case CSET_LINEDRW:
				tchar = term->ucsdata->unitab_xterm[tchar & 0xFF];
				break;
			case CSET_SCOACS:  
				tchar = term->ucsdata->unitab_scoacs[tchar&0xFF]; 
				break;
			}
			if (j < term->cols-1 && d[1].chr == UCSWIDE)
				tattr |= ATTR_WIDE;

			/* Video reversing things */
			if (term->selstate == DRAGGING || term->selstate == SELECTED) {
				if (term->seltype == LEXICOGRAPHIC)
					selected = (posle(term->selstart, scrpos) &&
					poslt(scrpos, term->selend));
				else
					selected = (posPle(term->selstart, scrpos) &&
					posPlt(scrpos, term->selend));
			} else
				selected = FALSE;
			tattr = (tattr ^ rv
				^ (selected ? ATTR_REVERSE : 0));

			/* 'Real' blinking ? */
			if (term->blink_is_real && (tattr & ATTR_BLINK)) {
				if (term->has_focus && term->tblinker) {
					tchar = term->ucsdata->unitab_line[(unsigned char)' '];
				}
				tattr &= ~ATTR_BLINK;
			}

			/*
			* Check the font we'll _probably_ be using to see if 
			* the character is wide when we don't want it to be.
			*/
			if (tchar != term->disptext[i]->chars[j].chr ||
				tattr != (term->disptext[i]->chars[j].attr &~
				(ATTR_NARROW | DATTR_MASK))) {
					if ((tattr & ATTR_WIDE) == 0 && char_width(ctx, tchar) == 2)
						tattr |= ATTR_NARROW;
			} else if (term->disptext[i]->chars[j].attr & ATTR_NARROW)
				tattr |= ATTR_NARROW;

			if (i == our_curs_y && j == our_curs_x) {
				tattr |= cursor;
				term->curstype = cursor;
				term->dispcursx = j;
				term->dispcursy = i;
			}

			/* FULL-TERMCHAR */
			newline[j].attr = tattr;
			newline[j].chr = tchar;
			/* Combining characters are still read from lchars */
			newline[j].cc_next = 0;
		}

		/*
		* Now loop over the line again, noting where things have
		* changed.
		* 
		* During this loop, we keep track of where we last saw
		* DATTR_STARTRUN. Any mismatch automatically invalidates
		* _all_ of the containing run that was last printed: that
		* is, any rectangle that was drawn in one go in the
		* previous update should be either left completely alone
		* or overwritten in its entirety. This, along with the
		* expectation that front ends clip all text runs to their
		* bounding rectangle, should solve any possible problems
		* with fonts that overflow their character cells.
		*/
		laststart = 0;
		dirtyrect = FALSE;
		for (j = 0; j < term->cols; j++) {
			if (term->disptext[i]->chars[j].attr & DATTR_STARTRUN) {
				laststart = j;
				dirtyrect = FALSE;
			}

			if (term->disptext[i]->chars[j].chr != newline[j].chr ||
				(term->disptext[i]->chars[j].attr &~ DATTR_MASK)
				!= newline[j].attr) {
					int k;

					if (!dirtyrect) {
						for (k = laststart; k < j; k++)
							term->disptext[i]->chars[k].attr |= ATTR_INVALID;

						dirtyrect = TRUE;
					}
			}

			if (dirtyrect)
				term->disptext[i]->chars[j].attr |= ATTR_INVALID;
		}

		/*
		* Finally, loop once more and actually do the drawing.
		*/
		dirty_run = dirty_line = (ldata->lattr !=
			term->disptext[i]->lattr);
		term->disptext[i]->lattr = ldata->lattr;

		for (j = 0; j < term->cols; j++) {
			unsigned long tattr, tchar;
			int break_run, do_copy;
			termchar *d = lchars + j;

			tattr = newline[j].attr;
			tchar = newline[j].chr;

			if ((term->disptext[i]->chars[j].attr ^ tattr) & ATTR_WIDE)
				dirty_line = TRUE;

			break_run = ((tattr ^ attr) & term->attr_mask) != 0;

#ifdef USES_VTLINE_HACK
			/* Special hack for VT100 Linedraw glyphs */
			if ((tchar >= 0x23BA && tchar <= 0x23BD) ||
				(j > 0 && (newline[j-1].chr >= 0x23BA &&
				newline[j-1].chr <= 0x23BD)))
				break_run = TRUE;
#endif

			/*
			* Separate out sequences of characters that have the
			* same CSET, if that CSET is a magic one.
			*/
			if (CSET_OF(tchar) != cset)
				break_run = TRUE;

			/*
			* Break on both sides of any combined-character cell.
			*/
			if (d->cc_next != 0 ||
				(j > 0 && d[-1].cc_next != 0))
				break_run = TRUE;

			if (!term->ucsdata->dbcs_screenfont && !dirty_line) {
				if (term->disptext[i]->chars[j].chr == tchar &&
					(term->disptext[i]->chars[j].attr &~ DATTR_MASK) == tattr)
					break_run = TRUE;
				else if (!dirty_run && ccount == 1)
					break_run = TRUE;
			}

			if (break_run) {
				if ((dirty_run || last_run_dirty) && ccount > 0) {
					do_text(ctx, start, i, ch, ccount, attr,
						ldata->lattr);
					if (attr & (TATTR_ACTCURS | TATTR_PASCURS))
						do_cursor(ctx, start, i, ch, ccount, attr,
						ldata->lattr);
				}
				start = j;
				ccount = 0;
				attr = tattr;
				cset = CSET_OF(tchar);
				if (term->ucsdata->dbcs_screenfont)
					last_run_dirty = dirty_run;
				dirty_run = dirty_line;
			}

			do_copy = FALSE;
			if (!termchars_equal_override(&term->disptext[i]->chars[j],
				d, tchar, tattr)) {
					do_copy = TRUE;
					dirty_run = TRUE;
			}

			if (ccount+2 > chlen) {
				chlen = ccount + 256;
				ch = sresize(ch, chlen, wchar_t);
			}

#ifdef PLATFORM_IS_UTF16
			if (tchar > 0x10000 && tchar < 0x110000) {
				ch[ccount++] = (wchar_t) HIGH_SURROGATE_OF(tchar);
				ch[ccount++] = (wchar_t) LOW_SURROGATE_OF(tchar);
			} else
#endif /* PLATFORM_IS_UTF16 */
				ch[ccount++] = (wchar_t) tchar;

			if (d->cc_next) {
				termchar *dd = d;

				while (dd->cc_next) {
					unsigned long schar;

					dd += dd->cc_next;

					schar = dd->chr;
					switch (schar & CSET_MASK) {
					case CSET_ASCII:
						schar = term->ucsdata->unitab_line[schar & 0xFF];
						break;
					case CSET_LINEDRW:
						schar = term->ucsdata->unitab_xterm[schar & 0xFF];
						break;
					case CSET_SCOACS:
						schar = term->ucsdata->unitab_scoacs[schar&0xFF];
						break;
					}

					if (ccount+2 > chlen) {
						chlen = ccount + 256;
						ch = sresize(ch, chlen, wchar_t);
					}

#ifdef PLATFORM_IS_UTF16
					if (schar > 0x10000 && schar < 0x110000) {
						ch[ccount++] = (wchar_t) HIGH_SURROGATE_OF(schar);
						ch[ccount++] = (wchar_t) LOW_SURROGATE_OF(schar);
					} else
#endif /* PLATFORM_IS_UTF16 */
						ch[ccount++] = (wchar_t) schar;
				}

				attr |= TATTR_COMBINING;
			}

			if (do_copy) {
				copy_termchar(term->disptext[i], j, d);
				term->disptext[i]->chars[j].chr = tchar;
				term->disptext[i]->chars[j].attr = tattr;
				if (start == j)
					term->disptext[i]->chars[j].attr |= DATTR_STARTRUN;
			}

			/* If it's a wide char step along to the next one. */
			if (tattr & ATTR_WIDE) {
				if (++j < term->cols) {
					d++;
					/*
					* By construction above, the cursor should not
					* be on the right-hand half of this character.
					* Ever.
					*/
					assert(!(i == our_curs_y && j == our_curs_x));
					if (!termchars_equal(&term->disptext[i]->chars[j], d))
						dirty_run = TRUE;
					copy_termchar(term->disptext[i], j, d);
				}
			}
		}
		if (dirty_run && ccount > 0) {
			do_text(ctx, start, i, ch, ccount, attr,
				ldata->lattr);
			if (attr & (TATTR_ACTCURS | TATTR_PASCURS))
				do_cursor(ctx, start, i, ch, ccount, attr,
				ldata->lattr);
		}

		unlineptr(ldata);
	}

	sfree(newline);
	sfree(ch);
}

/*
* Invalidate the whole screen so it will be repainted in full.
*/
void term_invalidate(Terminal *term)
{
	int i, j;

	for (i = 0; i < term->rows; i++)
		for (j = 0; j < term->cols; j++)
			term->disptext[i]->chars[j].attr |= ATTR_INVALID;

	term_schedule_update(term);
}

/*
* Paint the window in response to a WM_PAINT message.
*/
void term_paint(Terminal *term, Context ctx,
	int left, int top, int right, int bottom, int immediately)
{
	int i, j;
	if (left < 0) left = 0;
	if (top < 0) top = 0;
	if (right >= term->cols) right = term->cols-1;
	if (bottom >= term->rows) bottom = term->rows-1;

	for (i = top; i <= bottom && i < term->rows; i++) {
		if ((term->disptext[i]->lattr & LATTR_MODE) == LATTR_NORM)
			for (j = left; j <= right && j < term->cols; j++)
				term->disptext[i]->chars[j].attr |= ATTR_INVALID;
		else
			for (j = left / 2; j <= right / 2 + 1 && j < term->cols; j++)
				term->disptext[i]->chars[j].attr |= ATTR_INVALID;
	}

	if (immediately) {
		do_paint (term, ctx, FALSE);
	} else {
		term_schedule_update(term);
	}
}

/*
* Attempt to scroll the scrollback. The second parameter gives the
* position we want to scroll to; the first is +1 to denote that
* this position is relative to the beginning of the scrollback, -1
* to denote it is relative to the end, and 0 to denote that it is
* relative to the current position.
*/
void term_scroll(Terminal *term, int rel, int where)
{
	int sbtop = -sblines(term);
#ifdef OPTIMISE_SCROLL
	int olddisptop = term->disptop;
	int shift;
#endif /* OPTIMISE_SCROLL */

	term->disptop = (rel < 0 ? 0 : rel > 0 ? sbtop : term->disptop) + where;
	if (term->disptop < sbtop)
		term->disptop = sbtop;
	if (term->disptop > 0)
		term->disptop = 0;
	update_sbar(term);
#ifdef OPTIMISE_SCROLL
	shift = (term->disptop - olddisptop);
	if (shift < term->rows && shift > -term->rows)
		scroll_display(term, 0, term->rows - 1, shift);
#endif /* OPTIMISE_SCROLL */
	term_update(term);
}

/*
* Scroll the scrollback to centre it on the beginning or end of the
* current selection, if any.
*/
void term_scroll_to_selection(Terminal *term, int which_end)
{
	pos target;
	int y;
	int sbtop = -sblines(term);

	if (term->selstate != SELECTED)
		return;
	if (which_end)
		target = term->selend;
	else
		target = term->selstart;

	y = target.y - term->rows/2;
	if (y < sbtop)
		y = sbtop;
	else if (y > 0)
		y = 0;
	term_scroll(term, -1, y);
}

/*
* Helper routine for clipme(): growing buffer.
*/
typedef struct {
	int buflen;		    /* amount of allocated space in textbuf/attrbuf */
	int bufpos;		    /* amount of actual data */
	wchar_t *textbuf;	    /* buffer for copied text */
	wchar_t *textptr;	    /* = textbuf + bufpos (current insertion point) */
	int *attrbuf;	    /* buffer for copied attributes */
	int *attrptr;	    /* = attrbuf + bufpos */
} clip_workbuf;

static void clip_addchar(clip_workbuf *b, wchar_t chr, int attr)
{
	if (b->bufpos >= b->buflen) {
		b->buflen *= 2;
		b->textbuf = sresize(b->textbuf, b->buflen, wchar_t);
		b->textptr = b->textbuf + b->bufpos;
		b->attrbuf = sresize(b->attrbuf, b->buflen, int);
		b->attrptr = b->attrbuf + b->bufpos;
	}
	*b->textptr++ = chr;
	*b->attrptr++ = attr;
	b->bufpos++;
}

static void clipme(Terminal *term, pos top, pos bottom, int rect, int desel)
{
	clip_workbuf buf;
	int old_top_x;
	int attr;

	buf.buflen = 5120;			
	buf.bufpos = 0;
	buf.textptr = buf.textbuf = snewn(buf.buflen, wchar_t);
	buf.attrptr = buf.attrbuf = snewn(buf.buflen, int);

	old_top_x = top.x;		       /* needed for rect==1 */

	while (poslt(top, bottom)) {
		int nl = FALSE;
		termline *ldata = lineptr(top.y);
		pos nlpos;

		/*
		* nlpos will point at the maximum position on this line we
		* should copy up to. So we start it at the end of the
		* line...
		*/
		nlpos.y = top.y;
		nlpos.x = term->cols;

		/*
		* ... move it backwards if there's unused space at the end
		* of the line (and also set `nl' if this is the case,
		* because in normal selection mode this means we need a
		* newline at the end)...
		*/
		if (!(ldata->lattr & LATTR_WRAPPED)) {
			while (nlpos.x &&
				IS_SPACE_CHR(ldata->chars[nlpos.x - 1].chr) &&
				!ldata->chars[nlpos.x - 1].cc_next &&
				poslt(top, nlpos))
				decpos(nlpos);
			if (poslt(nlpos, bottom))
				nl = TRUE;
		} else if (ldata->lattr & LATTR_WRAPPED2) {
			/* Ignore the last char on the line in a WRAPPED2 line. */
			decpos(nlpos);
		}

		/*
		* ... and then clip it to the terminal x coordinate if
		* we're doing rectangular selection. (In this case we
		* still did the above, so that copying e.g. the right-hand
		* column from a table doesn't fill with spaces on the
		* right.)
		*/
		if (rect) {
			if (nlpos.x > bottom.x)
				nlpos.x = bottom.x;
			nl = (top.y < bottom.y);
		}

		while (poslt(top, bottom) && poslt(top, nlpos)) {
#if 0
			char cbuf[16], *p;
			sprintf(cbuf, "<U+%04x>", (ldata[top.x] & 0xFFFF));
#else
			wchar_t cbuf[16], *p;
			int c;
			int x = top.x;

			if (ldata->chars[x].chr == UCSWIDE) {
				top.x++;
				continue;
			}

			while (1) {
				int uc = ldata->chars[x].chr;
				attr = ldata->chars[x].attr;

				switch (uc & CSET_MASK) {
				case CSET_LINEDRW:
					if (!term->rawcnp) {
						uc = term->ucsdata->unitab_xterm[uc & 0xFF];
						break;
					}
				case CSET_ASCII:
					uc = term->ucsdata->unitab_line[uc & 0xFF];
					break;
				case CSET_SCOACS:
					uc = term->ucsdata->unitab_scoacs[uc&0xFF];
					break;
				}
				switch (uc & CSET_MASK) {
				case CSET_ACP:
					uc = term->ucsdata->unitab_font[uc & 0xFF];
					break;
				case CSET_OEMCP:
					uc = term->ucsdata->unitab_oemcp[uc & 0xFF];
					break;
				}

				c = (uc & ~CSET_MASK);
#ifdef PLATFORM_IS_UTF16
				if (uc > 0x10000 && uc < 0x110000) {
					cbuf[0] = 0xD800 | ((uc - 0x10000) >> 10);
					cbuf[1] = 0xDC00 | ((uc - 0x10000) & 0x3FF);
					cbuf[2] = 0;
				} else
#endif
				{
					cbuf[0] = uc;
					cbuf[1] = 0;
				}

				if (DIRECT_FONT(uc)) {
					if (c >= ' ' && c != 0x7F) {
						char buf[4];
						WCHAR wbuf[4];
						int rv;
						if (is_dbcs_leadbyte(term->ucsdata->font_codepage, (BYTE) c)) {
							buf[0] = c;
							buf[1] = (char) (0xFF & ldata->chars[top.x + 1].chr);
							rv = mb_to_wc(term->ucsdata->font_codepage, 0, buf, 2, wbuf, 4);
							top.x++;
						} else {
							buf[0] = c;
							rv = mb_to_wc(term->ucsdata->font_codepage, 0, buf, 1, wbuf, 4);
						}

						if (rv > 0) {
							memcpy(cbuf, wbuf, rv * sizeof(wchar_t));
							cbuf[rv] = 0;
						}
					}
				}
#endif

				for (p = cbuf; *p; p++)
					clip_addchar(&buf, *p, attr);

				if (ldata->chars[x].cc_next)
					x += ldata->chars[x].cc_next;
				else
					break;
			}
			top.x++;
		}
		if (nl) {
			int i;
			for (i = 0; i < sel_nl_sz; i++)
				clip_addchar(&buf, sel_nl[i], 0);
		}
		top.y++;
		top.x = rect ? old_top_x : 0;

		unlineptr(ldata);
	}
#if SELECTION_NUL_TERMINATED
	clip_addchar(&buf, 0, 0);
#endif
	/* Finally, transfer all that to the clipboard. */
	write_clip(term->frontend, buf.textbuf, buf.attrbuf, buf.bufpos, desel);
	sfree(buf.textbuf);
	sfree(buf.attrbuf);
}

void term_copyall(Terminal *term)
{
	pos top;
	pos bottom;
	tree234 *screen = term->screen;
	top.y = -sblines(term);
	top.x = 0;
	bottom.y = find_last_nonempty_line(term, screen);
	bottom.x = term->cols;
	clipme(term, top, bottom, 0, TRUE);
}

/*
* The wordness array is mainly for deciding the disposition of the
* US-ASCII characters.
*/
static int wordtype(Terminal *term, int uc)
{
	struct ucsword {
		int start, end, ctype;
	};
	static const struct ucsword ucs_words[] = {
		{
			128, 160, 0}, {
				161, 191, 1}, {
					215, 215, 1}, {
						247, 247, 1}, {
							0x037e, 0x037e, 1},	       /* Greek question mark */
							{
								0x0387, 0x0387, 1},	       /* Greek ano teleia */
								{
									0x055a, 0x055f, 1},	       /* Armenian punctuation */
									{
										0x0589, 0x0589, 1},	       /* Armenian full stop */
										{
											0x0700, 0x070d, 1},	       /* Syriac punctuation */
											{
												0x104a, 0x104f, 1},	       /* Myanmar punctuation */
												{
													0x10fb, 0x10fb, 1},	       /* Georgian punctuation */
													{
														0x1361, 0x1368, 1},	       /* Ethiopic punctuation */
														{
															0x166d, 0x166e, 1},	       /* Canadian Syl. punctuation */
															{
																0x17d4, 0x17dc, 1},	       /* Khmer punctuation */
																{
																	0x1800, 0x180a, 1},	       /* Mongolian punctuation */
																	{
																		0x2000, 0x200a, 0},	       /* Various spaces */
																		{
																			0x2070, 0x207f, 2},	       /* superscript */
																			{
																				0x2080, 0x208f, 2},	       /* subscript */
																				{
																					0x200b, 0x27ff, 1},	       /* punctuation and symbols */
																					{
																						0x3000, 0x3000, 0},	       /* ideographic space */
																						{
																							0x3001, 0x3020, 1},	       /* ideographic punctuation */
																							{
																								0x303f, 0x309f, 3},	       /* Hiragana */
																								{
																									0x30a0, 0x30ff, 3},	       /* Katakana */
																									{
																										0x3300, 0x9fff, 3},	       /* CJK Ideographs */
																										{
																											0xac00, 0xd7a3, 3},	       /* Hangul Syllables */
																											{
																												0xf900, 0xfaff, 3},	       /* CJK Ideographs */
																												{
																													0xfe30, 0xfe6b, 1},	       /* punctuation forms */
																													{
																														0xff00, 0xff0f, 1},	       /* half/fullwidth ASCII */
																														{
																															0xff1a, 0xff20, 1},	       /* half/fullwidth ASCII */
																															{
																																0xff3b, 0xff40, 1},	       /* half/fullwidth ASCII */
																																{
																																	0xff5b, 0xff64, 1},	       /* half/fullwidth ASCII */
																																	{
																																		0xfff0, 0xffff, 0},	       /* half/fullwidth ASCII */
																																		{
																																			0, 0, 0}
	};
	const struct ucsword *wptr;

	switch (uc & CSET_MASK) {
	case CSET_LINEDRW:
		uc = term->ucsdata->unitab_xterm[uc & 0xFF];
		break;
	case CSET_ASCII:
		uc = term->ucsdata->unitab_line[uc & 0xFF];
		break;
	case CSET_SCOACS:  
		uc = term->ucsdata->unitab_scoacs[uc&0xFF]; 
		break;
	}
	switch (uc & CSET_MASK) {
	case CSET_ACP:
		uc = term->ucsdata->unitab_font[uc & 0xFF];
		break;
	case CSET_OEMCP:
		uc = term->ucsdata->unitab_oemcp[uc & 0xFF];
		break;
	}

	/* For DBCS fonts I can't do anything useful. Even this will sometimes
	* fail as there's such a thing as a double width space. :-(
	*/
	if (term->ucsdata->dbcs_screenfont &&
		term->ucsdata->font_codepage == term->ucsdata->line_codepage)
		return (uc != ' ');

	if (uc < 0x80)
		return term->wordness[uc];

	for (wptr = ucs_words; wptr->start; wptr++) {
		if (uc >= wptr->start && uc <= wptr->end)
			return wptr->ctype;
	}

	return 2;
}

/*
* Spread the selection outwards according to the selection mode.
*/
static pos sel_spread_half(Terminal *term, pos p, int dir)
{
	termline *ldata;
	short wvalue;
	int topy = -sblines(term);

	ldata = lineptr(p.y);

	switch (term->selmode) {
	case SM_CHAR:
		/*
		* In this mode, every character is a separate unit, except
		* for runs of spaces at the end of a non-wrapping line.
		*/
		if (!(ldata->lattr & LATTR_WRAPPED)) {
			termchar *q = ldata->chars + term->cols;
			while (q > ldata->chars &&
				IS_SPACE_CHR(q[-1].chr) && !q[-1].cc_next)
				q--;
			if (q == ldata->chars + term->cols)
				q--;
			if (p.x >= q - ldata->chars)
				p.x = (dir == -1 ? q - ldata->chars : term->cols - 1);
		}
		break;
	case SM_WORD:
		/*
		* In this mode, the units are maximal runs of characters
		* whose `wordness' has the same value.
		*/
		wvalue = wordtype(term, UCSGET(ldata->chars, p.x));
		if (dir == +1) {
			while (1) {
				int maxcols = (ldata->lattr & LATTR_WRAPPED2 ?
					term->cols-1 : term->cols);
				if (p.x < maxcols-1) {
					if (wordtype(term, UCSGET(ldata->chars, p.x+1)) == wvalue)
						p.x++;
					else
						break;
				} else {
					if (p.y+1 < term->rows && 
						(ldata->lattr & LATTR_WRAPPED)) {
							termline *ldata2;
							ldata2 = lineptr(p.y+1);
							if (wordtype(term, UCSGET(ldata2->chars, 0))
								== wvalue) {
									p.x = 0;
									p.y++;
									unlineptr(ldata);
									ldata = ldata2;
							} else {
								unlineptr(ldata2);
								break;
							}
					} else
						break;
				}
			}
		} else {
			while (1) {
				if (p.x > 0) {
					if (wordtype(term, UCSGET(ldata->chars, p.x-1)) == wvalue)
						p.x--;
					else
						break;
				} else {
					termline *ldata2;
					int maxcols;
					if (p.y <= topy)
						break;
					ldata2 = lineptr(p.y-1);
					maxcols = (ldata2->lattr & LATTR_WRAPPED2 ?
						term->cols-1 : term->cols);
					if (ldata2->lattr & LATTR_WRAPPED) {
						if (wordtype(term, UCSGET(ldata2->chars, maxcols-1))
							== wvalue) {
								p.x = maxcols-1;
								p.y--;
								unlineptr(ldata);
								ldata = ldata2;
						} else {
							unlineptr(ldata2);
							break;
						}
					} else
						break;
				}
			}
		}
		break;
	case SM_LINE:
		/*
		* In this mode, every line is a unit.
		*/
		p.x = (dir == -1 ? 0 : term->cols - 1);
		break;
	}

	unlineptr(ldata);
	return p;
}

static void sel_spread(Terminal *term)
{
	if (term->seltype == LEXICOGRAPHIC) {
		term->selstart = sel_spread_half(term, term->selstart, -1);
		decpos(term->selend);
		term->selend = sel_spread_half(term, term->selend, +1);
		incpos(term->selend);
	}
}

static void term_paste_callback(void *vterm)
{
	Terminal *term = (Terminal *)vterm;

	if (term->paste_len == 0)
		return;

	while (term->paste_pos < term->paste_len) {
		int n = 0;
		while (n + term->paste_pos < term->paste_len) {
			if (term->paste_buffer[term->paste_pos + n++] == '\015')
				break;
		}
		if (term->ldisc)
			luni_send(term->ldisc, term->paste_buffer + term->paste_pos, n, 0);
		term->paste_pos += n;

		if (term->paste_pos < term->paste_len) {
			queue_toplevel_callback(term_paste_callback, term);
			return;
		}
	}
	sfree(term->paste_buffer);
	term->paste_buffer = NULL;
	term->paste_len = 0;
}

void term_do_paste(Terminal *term)
{
	wchar_t *data;
	int len;

	get_clip(term->frontend, &data, &len);
	if (data && len > 0) {
		wchar_t *p, *q;

		term_seen_key_event(term);     /* pasted data counts */

		if (term->paste_buffer)
			sfree(term->paste_buffer);
		term->paste_pos = term->paste_len = 0;
		term->paste_buffer = snewn(len + 12, wchar_t);

		if (term->bracketed_paste) {
			memcpy(term->paste_buffer, L"\033[200~", 6 * sizeof(wchar_t));
			term->paste_len += 6;
		}

		p = q = data;
		while (p < data + len) {
			while (p < data + len &&
				!(p <= data + len - sel_nl_sz &&
				!memcmp(p, sel_nl, sizeof(sel_nl))))
				p++;

			{
				int i;
				for (i = 0; i < p - q; i++) {
					term->paste_buffer[term->paste_len++] = q[i];
				}
			}

			if (p <= data + len - sel_nl_sz &&
				!memcmp(p, sel_nl, sizeof(sel_nl))) {
					term->paste_buffer[term->paste_len++] = '\015';
					p += sel_nl_sz;
			}
			q = p;
		}

		if (term->bracketed_paste) {
			memcpy(term->paste_buffer + term->paste_len,
				L"\033[201~", 6 * sizeof(wchar_t));
			term->paste_len += 6;
		}

		/* Assume a small paste will be OK in one go. */
		if (term->paste_len < 256) {
			if (term->ldisc)
				luni_send(term->ldisc, term->paste_buffer, term->paste_len, 0);
			if (term->paste_buffer)
				sfree(term->paste_buffer);
			term->paste_buffer = 0;
			term->paste_pos = term->paste_len = 0;
		}
	}
	get_clip(term->frontend, NULL, NULL);

	queue_toplevel_callback(term_paste_callback, term);
}

void term_mouse(Terminal *term, Mouse_Button braw, Mouse_Button bcooked,
	Mouse_Action a, int x, int y, int shift, int ctrl, int alt)
{
	pos selpoint;
	termline *ldata;
	int raw_mouse = (term->xterm_mouse &&
		!term->no_mouse_rep &&
		!(term->mouse_override && shift));
	int default_seltype;

	if (y < 0) {
		y = 0;
		if (a == MA_DRAG && !raw_mouse)
			term_scroll(term, 0, -1);
	}
	if (y >= term->rows) {
		y = term->rows - 1;
		if (a == MA_DRAG && !raw_mouse)
			term_scroll(term, 0, +1);
	}
	if (x < 0) {
		if (y > 0) {
			x = term->cols - 1;
			y--;
		} else
			x = 0;
	}
	if (x >= term->cols)
		x = term->cols - 1;

	selpoint.y = y + term->disptop;
	ldata = lineptr(selpoint.y);

	if ((ldata->lattr & LATTR_MODE) != LATTR_NORM)
		x /= 2;

	/*
	* Transform x through the bidi algorithm to find the _logical_
	* click point from the physical one.
	*/
	if (term_bidi_line(term, ldata, y) != NULL) {
		x = term->post_bidi_cache[y].backward[x];
	}

	selpoint.x = x;
	unlineptr(ldata);

	/*
	* If we're in the middle of a selection operation, we ignore raw
	* mouse mode until it's done (we must have been not in raw mouse
	* mode when it started).
	* This makes use of Shift for selection reliable, and avoids the
	* host seeing mouse releases for which they never saw corresponding
	* presses.
	*/
	if (raw_mouse &&
		(term->selstate != ABOUT_TO) && (term->selstate != DRAGGING)) {
			int encstate = 0, r, c, wheel;
			char abuf[32];
			int len = 0;

			if (term->ldisc) {

				switch (braw) {
				case MBT_LEFT:
					encstate = 0x00;	       /* left button down */
					wheel = FALSE;
					break;
				case MBT_MIDDLE:
					encstate = 0x01;
					wheel = FALSE;
					break;
				case MBT_RIGHT:
					encstate = 0x02;
					wheel = FALSE;
					break;
				case MBT_WHEEL_UP:
					encstate = 0x40;
					wheel = TRUE;
					break;
				case MBT_WHEEL_DOWN:
					encstate = 0x41;
					wheel = TRUE;
					break;
				default:
					return;
				}
				if (wheel) {
					/* For mouse wheel buttons, we only ever expect to see
					* MA_CLICK actions, and we don't try to keep track of
					* the buttons being 'pressed' (since without matching
					* click/release pairs that's pointless). */
					if (a != MA_CLICK)
						return;
				} else switch (a) {
				case MA_DRAG:
					if (term->xterm_mouse == 1)
						return;
					encstate += 0x20;
					break;
				case MA_RELEASE:
					/* If multiple extensions are enabled, the xterm 1006 is used, so it's okay to check for only that */
					if (!term->xterm_extended_mouse)
						encstate = 0x03;
					term->mouse_is_down = 0;
					break;
				case MA_CLICK:
					if (term->mouse_is_down == braw)
						return;
					term->mouse_is_down = braw;
					break;
				default:
					return;
				}
				if (shift)
					encstate += 0x04;
				if (ctrl)
					encstate += 0x10;
				r = y + 1;
				c = x + 1;

				/* Check the extensions in decreasing order of preference. Encoding the release event above assumes that 1006 comes first. */
				if (term->xterm_extended_mouse) {
					len = sprintf(abuf, "\033[<%d;%d;%d%c", encstate, c, r, a == MA_RELEASE ? 'm' : 'M');
				} else if (term->urxvt_extended_mouse) {
					len = sprintf(abuf, "\033[%d;%d;%dM", encstate + 32, c, r);
				} else if (c <= 223 && r <= 223) {
					len = sprintf(abuf, "\033[M%c%c%c", encstate + 32, c + 32, r + 32);
				}
				if (len > 0)
					ldisc_send(term->ldisc, abuf, len, 0);
			}
			return;
	}

	/*
	* Set the selection type (rectangular or normal) at the start
	* of a selection attempt, from the state of Alt.
	*/
	if (!alt ^ !term->rect_select)
		default_seltype = RECTANGULAR;
	else
		default_seltype = LEXICOGRAPHIC;

	if (term->selstate == NO_SELECTION) {
		term->seltype = default_seltype;
	}

	if (bcooked == MBT_SELECT && a == MA_CLICK) {
		deselect(term);
		term->selstate = ABOUT_TO;
		term->seltype = default_seltype;
		term->selanchor = selpoint;
		term->selmode = SM_CHAR;
	} else if (bcooked == MBT_SELECT && (a == MA_2CLK || a == MA_3CLK)) {
		deselect(term);
		term->selmode = (a == MA_2CLK ? SM_WORD : SM_LINE);
		term->selstate = DRAGGING;
		term->selstart = term->selanchor = selpoint;
		term->selend = term->selstart;
		incpos(term->selend);
		sel_spread(term);
	} else if ((bcooked == MBT_SELECT && a == MA_DRAG) ||
		(bcooked == MBT_EXTEND && a != MA_RELEASE)) {
			if (a == MA_DRAG &&
				(term->selstate == NO_SELECTION || term->selstate == SELECTED)) {
					/*
					* This can happen if a front end has passed us a MA_DRAG
					* without a prior MA_CLICK. OS X GTK does so, for
					* example, if the initial button press was eaten by the
					* WM when it activated the window in the first place. The
					* nicest thing to do in this situation is to ignore
					* further drags, and wait for the user to click in the
					* window again properly if they want to select.
					*/
					return;
			}
			if (term->selstate == ABOUT_TO && poseq(term->selanchor, selpoint))
				return;
			if (bcooked == MBT_EXTEND && a != MA_DRAG &&
				term->selstate == SELECTED) {
					if (term->seltype == LEXICOGRAPHIC) {
						/*
						* For normal selection, we extend by moving
						* whichever end of the current selection is closer
						* to the mouse.
						*/
						if (posdiff(selpoint, term->selstart) <
							posdiff(term->selend, term->selstart) / 2) {
								term->selanchor = term->selend;
								decpos(term->selanchor);
						} else {
							term->selanchor = term->selstart;
						}
					} else {
						/*
						* For rectangular selection, we have a choice of
						* _four_ places to put selanchor and selpoint: the
						* four corners of the selection.
						*/
						if (2*selpoint.x < term->selstart.x + term->selend.x)
							term->selanchor.x = term->selend.x-1;
						else
							term->selanchor.x = term->selstart.x;

						if (2*selpoint.y < term->selstart.y + term->selend.y)
							term->selanchor.y = term->selend.y;
						else
							term->selanchor.y = term->selstart.y;
					}
					term->selstate = DRAGGING;
			}
			if (term->selstate != ABOUT_TO && term->selstate != DRAGGING)
				term->selanchor = selpoint;
			term->selstate = DRAGGING;
			if (term->seltype == LEXICOGRAPHIC) {
				/*
				* For normal selection, we set (selstart,selend) to
				* (selpoint,selanchor) in some order.
				*/
				if (poslt(selpoint, term->selanchor)) {
					term->selstart = selpoint;
					term->selend = term->selanchor;
					incpos(term->selend);
				} else {
					term->selstart = term->selanchor;
					term->selend = selpoint;
					incpos(term->selend);
				}
			} else {
				/*
				* For rectangular selection, we may need to
				* interchange x and y coordinates (if the user has
				* dragged in the -x and +y directions, or vice versa).
				*/
				term->selstart.x = min(term->selanchor.x, selpoint.x);
				term->selend.x = 1+max(term->selanchor.x, selpoint.x);
				term->selstart.y = min(term->selanchor.y, selpoint.y);
				term->selend.y =   max(term->selanchor.y, selpoint.y);
			}
			sel_spread(term);
	} else if ((bcooked == MBT_SELECT || bcooked == MBT_EXTEND) &&
		a == MA_RELEASE) {
			if (term->selstate == DRAGGING) {
				/*
				* We've completed a selection. We now transfer the
				* data to the clipboard.
				*/
				clipme(term, term->selstart, term->selend,
					(term->seltype == RECTANGULAR), FALSE);
				term->selstate = SELECTED;
			} else
				term->selstate = NO_SELECTION;
	} else if (bcooked == MBT_PASTE
		&& (a == MA_CLICK
#if MULTICLICK_ONLY_EVENT
		|| a == MA_2CLK || a == MA_3CLK
#endif
		)) {
			request_paste(term->frontend);
	}

	/*
	* Since terminal output is suppressed during drag-selects, we
	* should make sure to write any pending output if one has just
	* finished.
	*/
	if (term->selstate != DRAGGING)
		term_out(term);
	term_update(term);
}

int format_arrow_key(char *buf, Terminal *term, int xkey, int ctrl)
{
	char *p = buf;

	if (term->vt52_mode)
		p += sprintf((char *) p, "\x1B%c", xkey);
	else {
		int app_flg = (term->app_cursor_keys && !term->no_applic_c);
#if 0
		/*
		* RDB: VT100 & VT102 manuals both state the app cursor
		* keys only work if the app keypad is on.
		*
		* SGT: That may well be true, but xterm disagrees and so
		* does at least one application, so I've #if'ed this out
		* and the behaviour is back to PuTTY's original: app
		* cursor and app keypad are independently switchable
		* modes. If anyone complains about _this_ I'll have to
		* put in a configurable option.
		*/
		if (!term->app_keypad_keys)
			app_flg = 0;
#endif
		/* Useful mapping of Ctrl-arrows */
		if (ctrl)
			app_flg = !app_flg;

		if (app_flg)
			p += sprintf((char *) p, "\x1BO%c", xkey);
		else
			p += sprintf((char *) p, "\x1B[%c", xkey);
	}

	return p - buf;
}

void term_nopaste(Terminal *term)
{
	if (term->paste_len == 0)
		return;
	sfree(term->paste_buffer);
	term->paste_buffer = NULL;
	term->paste_len = 0;
}

static void deselect(Terminal *term)
{
	term->selstate = NO_SELECTION;
	term->selstart.x = term->selstart.y = term->selend.x = term->selend.y = 0;
}

void term_deselect(Terminal *term)
{
	deselect(term);
	term_update(term);

	/*
	* Since terminal output is suppressed during drag-selects, we
	* should make sure to write any pending output if one has just
	* finished.
	*/
	if (term->selstate != DRAGGING)
		term_out(term);
}

int term_ldisc(Terminal *term, int option)
{
	if (option == LD_ECHO)
		return term->term_echoing;
	if (option == LD_EDIT)
		return term->term_editing;
	return FALSE;
}

int term_data(Terminal *term, int is_stderr, const char *data, int len)
{
	bufchain_add(&term->inbuf, data, len);

	if (!term->in_term_out) {
		term->in_term_out = TRUE;
		term_reset_cblink(term);
		/*
		* During drag-selects, we do not process terminal input,
		* because the user will want the screen to hold still to
		* be selected.
		*/
		if (term->selstate != DRAGGING)
			term_out(term);
		term->in_term_out = FALSE;
	}

	/*
	* term_out() always completely empties inbuf. Therefore,
	* there's no reason at all to return anything other than zero
	* from this function, because there _can't_ be a question of
	* the remote side needing to wait until term_out() has cleared
	* a backlog.
	*
	* This is a slightly suboptimal way to deal with SSH-2 - in
	* principle, the window mechanism would allow us to continue
	* to accept data on forwarded ports and X connections even
	* while the terminal processing was going slowly - but we
	* can't do the 100% right thing without moving the terminal
	* processing into a separate thread, and that might hurt
	* portability. So we manage stdout buffering the old SSH-1 way:
	* if the terminal processing goes slowly, the whole SSH
	* connection stops accepting data until it's ready.
	*
	* In practice, I can't imagine this causing serious trouble.
	*/
	return 0;
}

/*
* Write untrusted data to the terminal.
* The only control character that should be honoured is \n (which
* will behave as a CRLF).
*/
int term_data_untrusted(Terminal *term, const char *data, int len)
{
	int i;
	/* FIXME: more sophisticated checking? */
	for (i = 0; i < len; i++) {
		if (data[i] == '\n')
			term_data(term, 1, "\r\n", 2);
		else if (data[i] & 0x60)
			term_data(term, 1, data + i, 1);
	}
	return 0; /* assumes that term_data() always returns 0 */
}

void term_provide_logctx(Terminal *term, void *logctx)
{
	term->logctx = logctx;
}

void term_set_focus(Terminal *term, int has_focus)
{
	term->has_focus = has_focus;
	term_schedule_cblink(term);
}

/*
* Provide "auto" settings for remote tty modes, suitable for an
* application with a terminal window.
*/
char *term_get_ttymode(Terminal *term, const char *mode)
{
	const char *val = NULL;
	if (strcmp(mode, "ERASE") == 0) {
		val = term->bksp_is_delete ? "^?" : "^H";
	} else if (strcmp(mode, "IUTF8") == 0) {
		val = frontend_is_utf8(term->frontend) ? "yes" : "no";
	}
	/* FIXME: perhaps we should set ONLCR based on lfhascr as well? */
	/* FIXME: or ECHO and friends based on local echo state? */
	return dupstr(val);
}

struct term_userpass_state {
	size_t curr_prompt;
	int done_prompt;	/* printed out prompt yet? */
	size_t pos;		/* cursor position */
};

/*
* Process some terminal data in the course of username/password
* input.
*/
int term_get_userpass_input(Terminal *term, prompts_t *p,
	const unsigned char *in, int inlen)
{
	struct term_userpass_state *s = (struct term_userpass_state *)p->data;
	if (!s) {
		/*
		* First call. Set some stuff up.
		*/
		p->data = s = snew(struct term_userpass_state);
		s->curr_prompt = 0;
		s->done_prompt = 0;
		/* We only print the `name' caption if we have to... */
		if (p->name_reqd && p->name) {
			size_t l = strlen(p->name);
			term_data_untrusted(term, p->name, l);
			if (p->name[l-1] != '\n')
				term_data_untrusted(term, "\n", 1);
		}
		/* ...but we always print any `instruction'. */
		if (p->instruction) {
			size_t l = strlen(p->instruction);
			term_data_untrusted(term, p->instruction, l);
			if (p->instruction[l-1] != '\n')
				term_data_untrusted(term, "\n", 1);
		}
		/*
		* Zero all the results, in case we abort half-way through.
		*/
		{
			int i;
			for (i = 0; i < (int)p->n_prompts; i++)
				prompt_set_result(p->prompts[i], "");
		}
	}

	while (s->curr_prompt < p->n_prompts) {

		prompt_t *pr = p->prompts[s->curr_prompt];
		int finished_prompt = 0;

		if (!s->done_prompt) {
			term_data_untrusted(term, pr->prompt, strlen(pr->prompt));
			s->done_prompt = 1;
			s->pos = 0;
		}

		/* Breaking out here ensures that the prompt is printed even
		* if we're now waiting for user data. */
		if (!in || !inlen) break;

		/* FIXME: should we be using local-line-editing code instead? */
		while (!finished_prompt && inlen) {
			char c = *in++;
			inlen--;
			switch (c) {
			case 10:
			case 13:
				term_data(term, 0, "\r\n", 2);
				prompt_ensure_result_size(pr, s->pos + 1);
				pr->result[s->pos] = '\0';
				/* go to next prompt, if any */
				s->curr_prompt++;
				s->done_prompt = 0;
				finished_prompt = 1; /* break out */
				break;
			case 8:
			case 127:
				if (s->pos > 0) {
					if (pr->echo)
						term_data(term, 0, "\b \b", 3);
					s->pos--;
				}
				break;
			case 21:
			case 27:
				while (s->pos > 0) {
					if (pr->echo)
						term_data(term, 0, "\b \b", 3);
					s->pos--;
				}
				break;
			case 3:
			case 4:
				/* Immediate abort. */
				term_data(term, 0, "\r\n", 2);
				sfree(s);
				p->data = NULL;
				return 0; /* user abort */
			default:
				/*
				* This simplistic check for printability is disabled
				* when we're doing password input, because some people
				* have control characters in their passwords.
				*/
				if (!pr->echo || (c >= ' ' && c <= '~') ||
					((unsigned char) c >= 160)) {
						prompt_ensure_result_size(pr, s->pos + 1);
						pr->result[s->pos++] = c;
						if (pr->echo)
							term_data(term, 0, &c, 1);
				}
				break;
			}
		}

	}

	if (s->curr_prompt < p->n_prompts) {
		return -1; /* more data required */
	} else {
		sfree(s);
		p->data = NULL;
		return +1; /* all done */
	}
}
